The author(s) shown below used Federal funds provided by the U.S. 

Department of Justice and prepared the following final report:

Document Title: Accessing the Probative Value of Physical 

Evidence at Crime Scenes with Ambient Mass 

Spectrometry and Portable Instrumentation

Author(s): Christopher C. Mulligan, Ph.D., Adam E. O’Leary

Document No.: 248884

Date Received: May 2015

Award Number: 2011-DN-BX-K552

This report has not been published by the U.S. Department of Justice. 

To provide better customer service, NCJRS has made this federally 

funded grant report available electronically. 

Opinions or points of view expressed are those 

of the author(s) and do not necessarily reflect 

the official position or policies of the U.S. 

Department of Justice.
Accessing the Probative Value of Physical Evidence at 

Crime Scenes with Ambient Mass Spectrometry 

and Portable Instrumentation 

Award No. 2011-DN-BX-K552

Applied Research and Development in 

Forensic Science for Criminal Justice Purposes 

Final Report 

Prepared For 

U.S. Department of Justice 

Office of Justice Programs 

National Institute of Justice 

810 Seventh Street NW 

Washington, DC 20531

Prepared By 

Dr. Christopher C. Mulligan 

Department of Chemistry 

Illinois State University 

Normal, IL 61790 

and

Adam E. O’Leary 

Department of Chemistry 

Illinois State University 

Normal, IL 61790 

 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
i 

Abstract

The amount and variety of evidence collected at a typical crime scene is extensive. 

While many significant analytical methods have been established over the years, particularly 

hyphenated mass spectrometric techniques, forensic laboratories cannot keep up with the 

demand, and in many cases, significant backlogs of evidence have amassed. While this points to 

a need for more rapid, streamlined technologies for forensic analysis, a significant reduction in 

collected evidence, leading to a subsequent reduction in backlogged evidence, would come from 

the ability to access the probative value of chemical evidence at the crime scene itself, allowing 

only pertinent samples to be sent to off-site laboratories for confirmation. Screening of physical 

evidence at the crime scene also has the capability to rapidly determine whether a criminal 

investigation is needed and provide law enforcement personnel with necessary information in a 

timely manner, which in many cases is crucial. To assist in the reduction of collected samples 

while increasing the overall quality of said evidence, it would beneficial for forensic science 

practitioners to have technology at their disposal that is not only portable, allowing the screening 

of potential evidence before collection, but also flexible in terms of chemical species and sample 

substrates that can be analyzed. This flexibility, in particular, would allow this technology to be 

robust towards the ingenuity of criminals and emerging threats. 

In an effort to fulfill the current technological needs of forensic science practitioners and 

associated laboratories, we sought to create a broadly-applicable, portable chemical detector 

based on a state-of-the-art mass spectrometer (MS) capable of sampling externally-generated 

ions. This capability allows the use of novel “ambient” ionization methods that allow direct 

screening of target compounds or “analytes” in their native environment and state without prior 

preparation. Utilizing the Flir Systems AI-MS 1.2 portable instrument as a testbed, several 

ambient ionization techniques were created and/or validated for coupling to the system. The 

suite of ionization sources investigated allowed the sensitive analysis of solid, liquid, and gasphase chemicals, as well as chemical traces on everyday surfaces, at low concentrations with 

high chemical specificity. Swab-based physical transfer methods were developed and extended 

to this instrumentation to allow the flexibility in analyzing geometrically-complex samples and 

large surface areas, as well. Ambient ionization techniques coupled to this portable system were 

shown to perform well when analyzing complex samples (i.e. bulk powders, chemical residues in 

latent fingerprints, pharmaceutical tablets, clandestine synthetic reaction products/apparatus etc.), 

authentic evidentiary seizures, and emerging threats. Base and tandem MS (MS/MS) spectra 

obtained on the AI-MS 1.2 were marked by high congruency to that collected or reported on labscale, commercial MS systems, showing high potential for adoption as an accepted technique in 

crime scene investigation and forensic analyses. Furthermore, automated library searching via 

data dependent scanning and chemical identification via MS/MS fragmentation spectra offers the 

potential for usage by non-technical operators, reducing the need for spectral interpretation by 

the end-user. 

Building upon their extensive characterization and evaluation of this technology and 

considering interactions with forensic science practitioners, project personnel developed and 

deliver a Flir Systems AI-MS 1.2 prototype with optimized instrumental methods to NIJ for 

evaluation and testing, along with appropriate operational documentation and a comprehensive 

spectral library. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
ii

Table of Contents 

Executive Summary ..................................................................................................................... iv

1. Introduction .............................................................................................................................. 1

1.1 Statement of the Problem .................................................................................................. 1

1.2 Relevant Literature Review .............................................................................................. 1

1.2.1 Current Forensic Analysis Technologies ................................................................... 1

1.2.2 Necessary Criteria of Field-Portable Detection Technologies ................................... 2

1.2.3 Field-Portable Mass Spectrometry ............................................................................. 2

1.2.4 Ambient Mass Spectrometry...................................................................................... 3

1.3 Rationale for the Research ................................................................................................ 5

2. Methods ..................................................................................................................................... 6

2.1 Instrumentation and Ionization Sources .......................................................................... 6

2.1.1 Flir Systems AI-MS 1.2 ............................................................................................. 6

2.1.2 MS and MS/MS Analysis .......................................................................................... 6

2.1.3 ESI and DESI ............................................................................................................. 6

2.1.4 LTP ............................................................................................................................ 7

2.1.5 PSI .............................................................................................................................. 7

2.1.6 APCI .......................................................................................................................... 7

2.1.7 GC-MS ....................................................................................................................... 8

2.2 Sample Preparation ............................................................................................................ 8

2.2.1 Standards and Liquid-Phase Samples ........................................................................ 8

2.2.2 Solid-Phase Samples and Powders ............................................................................ 9

2.2.3 Gas-Phase Samples .................................................................................................... 9

2.3 Analytical Characterization ............................................................................................ 10

2.3.1 Spectral Quality and Accuracy ................................................................................ 10

2.3.2 Limits of Detection and Quantitation ...................................................................... 10

2.3.3 Reliability (False Positive/False Negative Rates) .................................................... 11

3. Results ..................................................................................................................................... 12

3.1 Task 1: Test Proof of Concept Detection of Chemicals of Interest on the Flir Systems 

AI-MS 1.2 ................................................................................................................................ 12

3.1.1 Compatible Ionization Sources for Solid and/or Liquid-Phase Samples ................. 12

3.1.2 Data Quality and Broad Application to Forensic Chemical Analysis ..................... 15

3.1.3 Comparison of Spray and Ambient Ionization Methods ......................................... 20

3.1.4 Analysis of Unconventional Surfaces and Complex Samples ................................. 22

3.1.5 Negative-Ion Mode on the Flir AI-MS 1.2 .............................................................. 24

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
iii

3.1.6 Explosives Analysis and Implementation of LTP-MS ............................................ 24

3.1.7 Analytical Characterization ..................................................................................... 25

3.2 Task 2: Investigate Alternative Surface Sampling Methodologies .............................. 31

3.2.1 Wet vs. Dry Swabbing and Transfer Efficiencies .................................................... 33

3.2.2 Recommended Transfer Swabbing Protocol ........................................................... 34

3.3 Task 3: Demonstrate Direct Air Analysis Ability via APCI on the Flir Systems AIMS 1.2 ...................................................................................................................................... 35

3.3.1 Assessment of Detection Limits via APCI .............................................................. 38

3.3.2 Analysis of Mock Arson Evidence via APCI-MS ................................................... 38

3.4 Task 4: Develop Comprehensive Mass Spectral Libraries and Optimized Methods 

for Target Chemicals .............................................................................................................. 40

3.4.1 Semi-Automated Optimization of MS/MS Method Conditions .............................. 41

3.4.2 Automated Library Searching via Data Dependent Scanning ................................. 42

3.5 Task 5: Demonstrate Detection Capability of Materials of Interest at Clandestine 

Methamphetamine Labs and Investigate Other Forensic Applications ............................ 47

3.5.1 Identification of Common Tablets and Powdered Precursors for Methamphetamine 

Production ......................................................................................................................... 48

3.5.2 Detection of Methamphetamine Residue from Production and Storage Media ...... 49

3.5.3 Monitoring the Clandestine Synthesis of Methamphetamine via Ambient MS ...... 50

3.5.4 Analysis of Desomorphine, Codeine and Fentanyl.................................................. 56

3.6 Task 6: Conduct Field Experiments and Disseminate Findings to Practitioners....... 58

3.6.1 Synthetic Cathinone “Bath Salt” Evidence .............................................................. 58

3.6.2 Powder and Residue-Level Cocaine and Methamphetamine Evidence .................. 61

3.7 Task 7: Preparation of Deliverable Instrument and Associated Documentation ...... 62

4. Conclusions ............................................................................................................................. 63

4.1 Discussion of Findings .............................................................................................. 63

4.2 Implications for Policy and Practice ....................................................................... 63

4.3 Implications for Further Research .......................................................................... 64

5. References ............................................................................................................................... 64

6. Dissemination of Research Findings ..................................................................................... 67

Appendix A: Positive-Mode MS and MS/MS Spectral Database ........................................... 70

Appendix B: Negative-Mode MS and MS/MS Spectral Database ....................................... 124

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
iv

Executive Summary 

The amount and variety of evidence collected a typical crime scene is extensive. While 

many significant analytical methods have been established over the years, particularly 

hyphenated mass spectrometric techniques, forensic laboratories cannot keep up with the 

demand, and in many cases, significant backlogs of evidence have amassed. While this points to 

a need for more rapid, streamlined technologies for forensic analysis, a significant reduction in 

collected evidence, leading to a subsequent reduction in backlogged evidence, would come from 

the ability to access the probative value of chemical evidence at the crime scene itself, allowing 

only pertinent samples to be sent to off-site laboratories for confirmation. Screening of physical 

evidence at the crime scene also has the capability to rapidly determine whether a criminal 

investigation is needed and provide law enforcement personnel with necessary information in a 

timely manner, which in many cases is crucial. To assist in the reduction of collected samples 

while increasing the overall quality of said evidence, it would beneficial for forensic science 

practitioners to have technology at their disposal that is not only portable, allowing the screening 

of potential evidence before collection, but also flexible in terms of chemical species and sample 

substrates that can be analyzed. This flexibility, in particular, would allow this technology to be 

robust towards the ingenuity of criminals and emerging threats. 

In an effort to fulfill the current technological needs of forensic science practitioners and 

associated laboratories, we sought to create a broadly-applicable, portable chemical detector 

based on a state-of-the-art mass spectrometer (MS) capable of sampling externally-generated 

ions. This capability allows the use of novel “ambient” ionization methods that allow direct 

screening of target compounds or “analytes” in their native environment and state without prior 

preparation. Utilizing the Flir Systems AI-MS 1.2 portable instrument as a testbed, several 

ambient ionization techniques were created and/or validated for coupling to the system. The 

suite of ionization sources investigated allowed the sensitive analysis of solid, liquid, and gasphase chemicals, as well as chemical traces on everyday surfaces, at low concentrations with 

high chemical specificity. Swab-based physical transfer methods were developed and extended 

to this instrumentation to allow the flexibility in analyzing geometrically-complex samples and 

large surface areas, as well. Ambient ionization techniques coupled to this portable system were 

shown to perform well when analyzing complex samples (i.e. bulk powders, chemical residues in 

latent fingerprints, pharmaceutical tablets, clandestine synthetic reaction products/apparatus etc.), 

authentic evidentiary seizures, and emerging threats. Base and tandem MS (MS/MS) spectra 

obtained on the AI-MS 1.2 were marked by high congruency to that collected or reported on labscale, commercial MS systems, showing high potential for adoption as an accepted technique in 

crime scene investigation and forensic analyses. Furthermore, automated library searching via 

data dependent scanning and chemical identification via MS/MS fragmentation spectra offers the 

potential for usage by non-technical operators, reducing the need for spectral interpretation by 

the end-user. 

Building upon their extensive characterization and evaluation of this technology and 

considering interactions with forensic science practitioners, project personnel developed and 

deliver a Flir Systems AI-MS 1.2 prototype with optimized instrumental methods to NIJ for 

evaluation and testing, along with appropriate operational documentation and a comprehensive 

spectral library. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
v

ES.1 Project Goals 

Project goals for this research project centered around answering five (5) principle 

scientific questions in order to gauge performance and potential applicability: (i) can a portable 

mass spectrometer be adapted to allow direct analysis of solid, liquid, and gas-phase chemical 

species? (ii) can evidence be effectively screened in a non-destructive nature? (iii) is physical 

transfer of chemical residues more effective that direct surface analysis? (iv) is the developed 

technology on par with current methods in terms of reliability, reproducibility, selectivity, and 

sensitivity? (v) is this technology robust in terms of the current and changing needs of forensic 

science and law enforcement personnel? 

Seven discrete tasks were undertaken to develop and implement the first-ever portable 

MS system that allows screening of probable evidentiary samples at crime scenes, yet is flexible 

and broadly-applicable to many different classes of chemicals and surface substrates. We began 

by evaluating the use of electrospray ionization (ESI), desorption electrospray ionization (DESI), 

low temperature plasma (LTP), and atmospheric pressure chemical ionization (APCI) on Flir 

Systems AI-MS 1.2, producing high quality MS and MS/MS spectral data for over 70 analytes of 

forensic evidence; paper spray ionization (PSI) was examined to a lesser extent. The ability to 

screen chemicals of interest as trace residues from common surfaces found at crime scenes (e.g.

glass, plastic, metal) and as bulk powders was successfully demonstrated. Intensive investigation 

of the analytical performance of the Flir AI-MS 1.2 was then undertaken, including spectral data 

quality and accuracy, sensitivity and quantitative ability, sample throughput, and reliability in 

terms of false positive/false negative rates. Swab-based physical transfer methods were 

developed and extended to this instrumentation to allow the flexibility in analyzing 

geometrically-complex samples and large surface areas, as well. A custom APCI-MS source 

was developed and implemented on the system to extend application to high volatility analytes, 

particularly common accelerants pertinent to arson investigations, solvents used in clandestine 

drug operations, and chemical warfare agent simulants. Utilizing optimized instrumental 

methods developed in-house, a comprehensive mass spectral reference library consisting of both 

full scan and MS/MS fragmentation spectra was constructed to assist possible end users of the 

instrumentation. Prototypical, simplified user software methods allowing automated library 

searching and negating the need for spectral interpretation were developed and rigorously tested, 

showing high potential for use by non-technical operators. Proof of concept experiments were 

conducted to show application of the system to the daunting task of chemical identification at 

clandestine laboratory operations; toward this, the Flir AI-MS 1.2 performed well, easily 

identifying common illicits and their precursors as powders, tablets, and residues from surfaces 

and storage media. The ability to perform real-time reaction monitoring of clandestine 

methamphetamine production was also demonstrated; this, in essence, allows the Flir AI-MS 1.2 

to conclusively identify a clandestine methamphetamine operation regardless of synthesis stage. 

Field testing and demonstrations for forensic science and law enforcement personnel was 

pursued to demonstrate the technology on authentic contraband samples and seized materials. 

The culmination of the project was the preparation and delivery of a modified Flir AI-MS 1.2 

system coupled with the associated ionization sources, as well as associated training 

documentation, spectral libraries and methods, to the NIJ. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
vi 

ES.2 Methods Implemented During Project 

In all studies, a Flir Systems AI-MS 1.2 cylindrical ion trap (CIT) mass spectrometer (Flir 

Mass Spectrometry, West Lafayette, IN, USA) ruggedized of field use was implemented. This 

portable system allows sampling of externally-generated ions via a capillary-based atmospheric 

pressure inlet, and analyte confirmation is possible via tandem MS (MS/MS). All AC/DC 

voltages needed for instrument operation and desorption electrospray ionization (DESI) are 

incorporated, as well as an on-board helium supply for the CIT damping gas needed for MS/MS 

fragmentation. Nebulizing gas (N2 or air) necessary for DESI analysis is supplied by a standalone tank, allowing the use of small, self-contained breathing apparatus (SCBA) tanks 

commonly utilized by the first response community for field implementation. The size (24” x 

20” x 15”, L x W x H), weight (98 lbs.) and ruggedness of this instrument makes it an amenable 

platform for field-based, CSI applications. 

Over the course of the project, several conventional and ambient ionization sources were 

constructed and tested on the Flir AI-MS 1.2, including ESI (for solutions and extracts), DESI 

(for solids, powders, residues and transfer swabs), LTP (for residues), PSI (for powders, residues 

and transfer swabs), and APCI (for gas-phase analytes). For ESI and DESI studies, The AI-MS 

1.2 system has a position-stationary ionization assembly that allows implementation of both 

spray-based methods. The stationary source is mounted to fix both the ESI/DESI spray angle 

(55°) and DESI emitter tip-to-analysis surface distance. Spray parameters included a 4 kV spray 

voltage, nebulizing gas pressure (N2) of 100 PSI, and solvent flow rates of either 10 μL/min for 

ESI or 3 μL/min for DESI. All spray-based ionization was performed with spray solvent 

compositions consisting of 1:1 methanol:water with 0.1% formic acid in positive-ion mode and 

1:1 methanol:water in negative-ion mode. LTP was investigated extend application of the system 

to explosives, and was implemented constructing a custom source using a stock nanoESI holder 

with gas assistance port (Warner Instruments, ESW-M15P), through which helium gas is flowed 

at a rate of 0.2-0.3 L/min. To provide the necessary dielectric barrier, a quartz capillary (Sutter 

Instruments) is sheathed over the electrode of the nanoESI probe (grounded), to which a small 

section of adhesive-backed copper tape is wrapped and connected to the AC power supply 

(Information Unlimited, PVM500, 3-4 kV, 33.6 kHz) needed for plasma generation. PSI-MS 

works by combining two mechanisms, paper chromatographic separation and electrospraying. 

After a chemical is applied to the paper triangle (Whatman chromatography paper) by spotting or 

swab transfer, the combination of added solvent and 4 kV of high voltage provided by an onboard high voltage “alligator clip” electrode produces a stable electrospray of inherent analyte 

ions detected by the MS. For gas-phase analytes, a custom-built teflon APCI source featuring an 

auxiliary pumping system to sample volatile chemicals in proximity to the Flir Systems AI-MS 

1.2 was constructed. Inside the source, a corona discharge is generated by application of 4 kV 

under resistivity (1 MΩ) to a tungsten wire discharge needle held perpendicular to the MS inlet 

capillary. Before data collection on the portable MS system, instrument calibration and tuning 

was performed to provide optimal operating conditions. Mass spectral data was collected in 

either positive or negative-ion mode, depending on the nature of the chemical of interest. 

For characterization studies with ESI/DESI/LTP/PSI, analytical standards of illicit 

chemicals and others of forensic interest were purchased as either standard solutions (Cerilliant 

Co., Round Rock, TX, USA) or pure solids (Sigma-Aldrich Co., St Louis, MO, USA) in 1000 

ppm (1.0 mg/mL) concentrations. Serial dilution of the stock solutions were performed as 

desired using appropriate solvents, including HPLC-grade methanol and acetonitrile obtained 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
vii 

from Fisher Scientific (Pittsburg PA). Residues of known mass were deposited on substrates of 

interest for direct analysis experimentation (DESI/PSI/LTP) or swab transfer by spotting and 

drying small aliquot(s) of known concentration solutions. Powder-based samples and authentic 

forensic evidence was analyzed by deposited ~1 mg onto an adhesive-based glass slide or via 

swab transfer. Transfer swabbing procedures for DESI/PSI involved wetting the sampling 

medium with a predetermined amount of methanol to assist with efficient surface transfer and 

probing of the surface or sample of interest, followed by direct analysis of said swab without 

further preparation. Volatile analytes were examined via APCI-MS by sampling ambient air or 

headspace vapors from sealed flasks containing pure liquid chemicals (Sigma-Aldrich). 

 

ES.3 Results 

ES.3.1 Task 1: Test Proof of Concept Detection of Chemicals of Interest on the Flir Systems 

AI-MS 1.2 

Ambient ionization coupled with the Flir AI-MS 1.2 system has far exceeded our initial 

expectations in regards to performance and applicability to analytes and samples of interest to 

forensic science and crime scene investigation. At the time of writing, our database of detected 

and confirmed analytes numbers 73 and continues to grow as new and emerging illicits continue 

to be added. This spectral database contains MS and MS/MS from a wide array of illicit drugs, 

abused pharmaceuticals, potential cutting agents, explosives and species related to ballistics, and 

accelerants. For the analytes tested, all non-volatile species were analyzed at a deposited mass of 

100 ng via DESI-MS, the milestone amount targeted for this grantwork, unless they were directly 

analyzed via APCI due to volatility. Of note, a majority of the compounds tested produced very 

high spectral signal intensity even at 100 ng, meaning that most limits of detection for these 

species lie in the very low to sub-ng range. Spectral data collected on the AI-MS 1.2 was highly 

congruent in regards to both MS and MS/MS ion signatures collected on in-house, lab-scale MS 

instrumentation and also seen in scientific literature; this is seen as a major benefit towards 

actual implementation in CSI applications and potential acceptance as a validated method. When 

comparing spectra collected using ESI, DESI and PSI on a similar analyte, they are marked by 

high similarity in regards to ions seen; however, differences in signal intensities are seen 

depending the mechanisms employed by the ionization technique (i.e. DESI signal intensity is 

typically lower than that of ESI or PSI for similar mass of compound analyzed due to its required 

surface desorption mechanism). 

Analysis of residues from flat surfaces like glass or plastic was demonstrated with very 

high throughput and sensitivity, but given the potential complexity of authentic forensic evidence 

in terms of chemical composition, geometry, and size, experimentation on unconventional 

substrates and complex samples was thoroughly investigated. The Flir AI-MS 1.2 performed 

well in this testing, with the suite of ionization methods utilized proving robust to a wide 

selection of test samples. Over the course of the project, representative surfaces tested included 

glasses, metals, polymers/plastics, non-stick coatings, common paraphernalia, phone keypads, 

and many others. Detection of chemical signatures in latent fingerprints and organic components 

in gunshot residue was also successfully demonstrated. 

Spectral quality (in terms of accuracy of m/z determinations and relative abundance in 

both MS and MS/MS mode) of the Flir Systems AI-MS 1.2 was tested by direct comparison with 

a commercially-available, spectral reference database, the Wiley Registry® of Tandem Mass 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
viii 

Spectral Data (MSforID). To compare to the database, MS and MS/MS data using spray and 

ambient ionization techniques for thirty-two total “blind” analytes, including five negative 

controls were subjected to library searching, providing the correct identification for all positive 

controls tested with high sensitivity (i.e. true positive rate). Authentic seized evidence was also 

able to be rapidly identified, providing accurate determinations and demonstrating high potential 

for use in forensic casework and potential crime scene investigation.

Ambient MS analyses upon the Flir AI-MS 1.2 were marked by very high throughput, 

usually dictated by the user themselves (i.e. how quickly they can document a sample and 

present it for analysis), and well as little to no carryover. Reliability of the system was assessed 

by determination of false positive/false negative rates for lab-generated control samples, yielding 

100% success rate for positive controls and 98% success rate for negative controls for 400 

control samples. 

ES.3.2 Task 2: Investigate Alternative Surface Sampling Methodologies 

Analysis of surface swabs with DESI, following the probing of samples of interest, was 

successfully demonstrated from several surfaces of interest (e.g. latent fingerprints from 

touchscreen cellphone, prescription pill bottles, etc.) with relevance to drugs of abuse. The effect 

of surface probing with “wet” swabs vs. dry swabs was also evaluated. For this evaluation 

methanol, which has high solubility towards drugs of abuse, was utilized with wet swabbing. It 

was determined that wet swabbing drastically outperformed dry swabbing. Different swabs were 

also investigated for their applicability to direct DESI analysis, including chromatography paper, 

knitted polyester, non-woven hydroentangled foam polyester, polyurethane foam, and spun 

cotton “Q-Tip”-style applicators. Considering all factors tested, Berkshire polyurethane foam 

swabs were determined to be the best candidate for developing an optimized transfer swabbing 

protocol for use with DESI-MS. 

ES.3.3 Task 3: Demonstrate Direct Air Analysis via APCI on the Flir Systems AI-MS 1.2 

High volatility analytes have long been examined using GC/MS, but when implementing 

specialized ionization sources, they can also be analyzed on the Flir AI-MS 1.2 directly from 

ambient air. To demonstrate the ability to monitor gas-phase analytes directly from the air via 

APCI-MS, several iterations of source design were undertaken, producing a robust, sensitive 

ionization source easily coupled to the system without interference with the on-board ESI/DESI 

assembly. By utilizing a small auxiliary diaphragm pump, non-proximate, ambient air samples 

can be pulled into the APCI source for analysis via a sampling tube; this provides flexibility in 

what and where air samples are investigated. Vapors from an array of potential accelerants were 

investigated to show potential applicability to arson investigation evidence, and limits of 

detection for several of these were demonstrated to be less than 1 ppm (a milestone threshold for 

this grantwork). Mock arson evidence was created by combusting wood substrates in the 

presence of accelerants of interest, enclosing charred materials in sealed flasks, and sampling 

headspace vapors for detection. From the data collected, accelerants used for combustion are 

able to be detected, along with other signatures from chemicals inherent to the substrate itself.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
ix

ES.3.4 Task 4: Develop Comprehensive Mass Spectral Libraries and Optimized Methods for 

Target Chemicals 

Over the course of the project period, high-quality MS and MS/MS spectra and methods 

for their collection were generated for numerous analytes of forensic interest for development of 

a comprehensive mass spectral library. Optimization of MS/MS instrumental methods was 

undertaken by systematically adjusting ion trap parameters during precursor isolation and 

fragmentation, including frequency of the AC dissociation waveform applied, collision energy 

(i.e. the energy imparted to isolated ions via collision-induced dissociation, CID, with helium 

damping gas), and dissociation time. Said MS/MS methods not only gave fragmentation data 

congruent to our own testing on lab-scale MS instruments and that reported by other research 

groups in literature, but also have proven to be reproducible in both intra- and inter-day testing. 

User software upgrades released by Flir Mass Spectrometry for the AI-MS 1.2 allowed creation 

of semi-automated optimization methods of MS/MS experimental conditions and fullyautomated library searching protocols based of MS/MS-based data dependent scanning. Of note, 

automated library searching has the potential to alleviate the need for spectral interpretation by 

the instrument operator, expanding its use by non-technical operators by incorporating “red 

light/green light” protocols (i.e. red indications on a graphical user interface affirms the presence 

of a target analyte, green indications that the sample is innocuous). 

ES.3.5 Task 5: Demonstrate Detection Capability of Materials of Interest at Clandestine 

Methamphetamine Labs 

Clandestine laboratory installations represent the worst-case scenario for field analysis, as 

the variety of “samples” found are diverse in nature, of high magnitude, rarely marked and stored 

in proper containers, and most likely located in unsafe conditions. To help provide a robust 

platform for general sample screening in these situations, proof-of-principle experimentation on 

the Flir AI-MS 1.2 focused on synthetic routes for methamphetamine and the emerging 

clandestine drug desomorphine (aka “krokodil”). Testing during this phase of the project 

involved trace residues and bulk powder of precursors and illicit products, and potential solvents 

used in clandestine operations were examined via APCI-MS. Active ingredients in 

pharmaceutical and over-the-counter tablets utilized as a source of precursors can easily be 

identified as either bulk compositions or residues from production and storage media commonly 

found in clandestine settings. The AI-MS 1.2 was also shown able to monitor in real-time both 

the Birch reduction and Nagai synthetic routes for methamphetamine, identifying both precursor 

and product species at any point during the reactions. This, in essence, allows the Flir AI-MS 

1.2 to conclusively identify a clandestine methamphetamine operation regardless of synthesis 

stage. Preliminary results also point to the ability to confirm fentanyl clandestine synthesis. 

ES.3.6 Task 6: Conduct Field Experiments/Dissemination to Practitioners 

While many of the results obtained on the Flir AI-MS 1.2 during this project involved 

analytical standards in controlled laboratory settings, special efforts were taken to perform field 

testing on authentic forensic evidence. Field testing conducted with law enforcement, forensics 

and criminal justice practitioners served dual purposes, as the effect of environmental variables 

(i.e. transport and calibration, ambient conditions, etc.) can be assessed while gathering integral 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
x

feedback from the target user groups. Overall, practitioners who witnessed our demonstrations 

and field experimentation were impressed by the performance of the Flir AI-MS 1.2, size of the 

device, and especially by the ease of use. Through discussion with these groups, information 

regarding needs for true field implementation and use by untrained personnel was acquired that 

helped craft and improve our developed methods and ionization source design. Furthermore, 

important troubleshooting experiences were gathered during these exercises. 

Several opportunities to analyze authentic forensic evidence stemmed from these 

interactions, to which ambient MS on the Flir AI-MS 1.2 performed admirably. Evidence tested 

during this phase of the project included authentic synthetic cathinone “bath salt” powders that 

were seized as commercially-available products at local retailers, powdered cocaine, and 

methamphetamine residue on the inside of a plastic bag used to transport the drug. Of interest, 

experimentation with bulk forensic evidence was able to be accomplished without extensive 

carryover between analyses by implementing proper hygiene protocols involving cleaning of the 

ionization source and outer surface of the MS inlet capillary and analysis of pre-sample blanks. 

ES.3.7 Task 7: Preparation of Deliverable Instrument and Associated Documents 

An important final aspect of this project was to prepare and deliver a modified Flir AIMS 1.2 system coupled with the associated ionization sources investigated to the NIJ for testing 

purposes. Along with the instrumentation, a comprehensive mass spectral library (including MS 

and MS/MS data for project analytes) and optimized compound-specific MS/MS methods were 

delivered. Also, methods allowing automated library searching via data dependent scanning 

were able to be constructed and delivered. Documentation delivered with the Flir AI-MS 1.2 

included extensive training and troubleshooting manuals, with substantial detail to ensure that 

NIJ personnel and other users will be able to quickly learn the operation of all facets of the 

system. 

ES.4 Conclusions

The Flir Systems AI-MS 1.2 was demonstrated to be broadly-applicable, portable 

instrument with high potential for use in crime scene investigation and evidentiary analysis. The 

flexibility to screen and identify solid, liquid and gas-phase analyte when utilizing the suite of 

ionization methods developed and/or investigated on the system has the potential to provide 

capabilities that no other fieldable technology currently available can offer. Switching between 

trace level residues and bulk-level samples was achievable with no carryover when 

implementing simple hygiene protocols, and coupling with physical transfer swabs extends 

application of the system to large and geometrically-complex surfaces, meeting the demands that 

real evidence present. The congruency of spectral data collected on the AI-MS 1.2 in regards to 

both MS and MS/MS ion signatures collected on lab-scale MS instrumentation and also seen in 

scientific literature is seen as important milestone towards acceptance as a validated forensic 

analysis method and actual implementation in CSI applications.

 When considering the end product of this project, a portable instrument capable of 

assessing the probative value of physical evidence typically found at crime scenes, the impact of 

providing the forensic science community with said technology would have a positive effect on 

criminal justice practice at the local, state and national level. There are also potential 

implications in regards to reducing evidence backlogs that hinder publicly-funded forensic 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
xi

laboratories, as this technology provides both higher throughput and a potentially reduced influx 

of evidence entering the lab system. When considering the feasibility of implementing the 

proposed technology in forensic settings, the cost of this instrumentation and maintenance could 

be off-set by the reduction in evidence sent to forensic laboratories and funds being used for 

outsourced analyses to private laboratories. 

 While the effect on current criminal justice practice can be presumed, the implications on 

current criminal justice policy are not as clear. Field-portable units for accurate contraband 

detection in the condensed phase and from surfaces would allow greater versatility in routine 

traffic stops and criminal investigations, but if this technology is used to gather evidence prior to 

an arrest, there are implications regarding unreasonable search and seizures. Overall, 

implementation of the proposed research could allow greater flexibility in law enforcement, but 

its application to legal convictions under current criminal justice policy will need to be 

considered before common usage. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
1

1. Introduction 

1.1 Statement of the Problem 

It is hard to envision a more nebulous, demanding discipline than forensic science in terms 

of chemical analysis. The nature of forensic science suggests than almost any chemical could be 

potential evidence, given that it was involved in or alludes to criminal activities. To further 

complicate the issue, this large breadth of chemical species can be found in various states of 

matter, as residues on many different substrates, or in the presence of complex chemical 

matrices. Due to this, both the amount and variety of evidence collected is extensive. While 

several analytical techniques for identification and quantitation of unknown chemical species 

have been established for use in forensic science, they have had to be adapted over the years to 

incorporate high-throughput sampling into the instrumental method in an attempt to keep up with 

the magnitude of submitted evidence while still fulfilling the requirements of the legal system. 

While many significant analytical methods have been established, forensic laboratories cannot 

keep up with the demand, and in many cases, significant backlogs of evidence have amassed. 

The most notable example of this backlog is DNA evidence. While DNA profiling is 

regarded as one of the most discriminating and powerful types of evidence, many laboratories 

struggle to obtain needed results on a timeframe that is consistent with corresponding legal 

proceedings, requiring considerable outsourcing of evidentiary analyses. In fact, it was recently 

estimated that nearly half of publicly funded forensic laboratories outsourced at least one type of 

forensic service to private laboratories, which is disadvantageous from a budgetary standpoint.1 

While this points to a need for more rapid, streamlined technologies for forensic analysis, a 

significant reduction in collected evidence, leading to a subsequent reduction in backlogged 

evidence, would come from the ability to access the probative value of chemical evidence at the 

crime scene itself, allowing only pertinent samples to be sent to off-site laboratories for 

confirmation. Screening of physical evidence at the crime scene also has the capability to 

rapidly determine whether a criminal investigation is needed and provide law enforcement 

personnel with necessary information in a timely manner, which in many cases is crucial. To 

assist in the reduction of collected samples while increasing the overall quality of said evidence, 

it would beneficial for forensic science practitioners to have technology at their disposal that is 

not only portable, allowing the screening of potential evidence before collection, but also flexible 

in terms of chemical species and sample substrates that can be analyzed. This flexibility, in 

particular, would allow this technology to be robust towards the ingenuity of criminals and 

emerging threats. 

1.2 Relevant Literature Review

1.2.1 Current Forensic Analysis Technologies 

The field of forensic science has matured concurrently with advancements in analytical 

instrumentation. While several colorimetric assays are still implemented in the field and 

laboratory setting,2,3 a majority of forensic analyses have grown to incorporate instrumental 

methods with specific sample preparation requirements, and have become both routine and 

accepted as relevant in judicial proceedings. Instrumentation commonly utilized in the forensic 

laboratory setting for chemical analyses includes gas (GC) and liquid chromatography (LC) 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
2

coupled with mass spectrometry (MS) for illicit drug analyses, toxicology, and arson 

investigations, infrared spectroscopy (IR) for blood alcohol content, atomic spectroscopy for 

elemental speciation, and capillary electrophoresis (CE) for DNA profiling, and new 

methodologies are currently being investigated.4-6 While each of these technologies offers its 

own benefits, these techniques often require multiple instrumental methods to cover a broad 

range of analytes, suffer from long analysis times, and require extensive sample preparation, 

commonly in the form of liquid-liquid and solid phase extraction.

A significant disadvantage of these techniques is that they are confined to the laboratory 

(with the exception of a few GC-MS and IR portable systems currently available), requiring all 

potential evidence to be collected at the crime scene and sent back to laboratory facilities. This 

is disadvantageous in terms of chain of custody errors and sample degradation, but more 

importantly, the time between evidence collection and interpretation of chemical data is 

extensive. To combat this, several portable technologies have been investigated,7-9 but few have 

been introduced as commercial products. Manufacturers such as Inficon, Torion Technologies, 

and Griffin Analytical Technologies have introduced portable GC/MS instruments, which is a 

significant milestone given the substantial usage of GC/MS in forensic science, but these 

instruments have comparable, if not more extensive, sample preparation requirements and suffer 

from low sample throughput. 

1.2.2 Necessary Criteria of Field-Portable Detection Technologies 

To be considered a viable technology, portable analytical instruments have long been 

required to fulfill the three main analytical criteria of sensitivity, selectivity, and speed.10 

Sensitivity is required because compounds of interest are often at very low levels—parts per 

million to parts per billion. Selectivity in detection, or the ability to accurately discriminate the 

response from the desired target compound against other compounds present in the sample, is 

vital, given the complexity of samples of interest in their natural states or locations. Because 

important actions—such as arrests for criminal activities and closing of public venues–could be 

based on the response of such analytical instrumentation, selective detection is key in avoiding 

false alarms, or more importantly, false negative responses, where a target analyte is actually 

present but analysis yields a “negative” response for its presence. An instrument’s ability to 

provide real-time data for first responders at an incident site is also important. 

Considering the incidents that often involve forensic and law enforcement personnel and 

first responders, including arson investigations and domestic terrorism involving explosives and 

other harmful chemical/biological agents,11 the current criteria must be expanded for portable 

technologies to account for these situations. It is critical that the tools at the disposal of forensic 

science practitioners be versatile so that they are broadly applicable to incident sites and the 

samples of interest they contain, but also robust in terms of new threats and applications for 

which they will utilized. 

1.2.3 Field-Portable Mass Spectrometry 

Several technologies with varying levels of performance and feasibility have emerged as 

candidates for continued development and evaluation as portable analytical instruments, as 

recently reviewed.7-9 Of these technologies, several exhibit significant drawbacks, including long 

analysis times, high false positive and negative rates, high limits of detection, and narrow 

applicability. Mass spectrometry (MS) emerges as a technique with the potential of fulfilling 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
3

the major criteria needed for field-portable analytical instruments. Of the general-purpose 

methods of chemical analysis, mass spectrometry has proven to be one the most sensitive 

techniques, and detection of ultra-trace quantities of specific compounds has been reported, even 

from complex mixtures.10 The high specificity of MS comes from tandem mass spectrometric 

analysis (two or more coupled stages of mass analysis), which allows for both molecular weight 

and structural data to be gathered. 

 Recent advances in vacuum and electronic technologies have led to the miniaturization of 

MS instruments that make portability feasible. Several research groups have designed and 

reported portable MS prototypes,11-13 and on-site analysis with instruments typically requiring as 

little as 50 ms to acquire a complete mass spectrum leads to rapid collection of data. However, 

conventional sample preparation typically can take several hours to days, depending upon the 

sample in question and the desired analyte. Novel sample ionization methods at atmospheric 

pressure, or “ambient mass spectrometry,” have allowed mass spectrometric analysis to take

place with little to no sample preparation.14-16 These flexible ionization methods require that the 

instrumentation being employed allows for sampling of analyte ions at atmospheric pressure into 

the instrument’s vacuum system. Although this constraint typically requires large, power-hungry 

vacuum systems that are not amenable to fieldable mass spectrometers, portable17 and handheld18

MS prototypes have been developed to allow coupling to ambient mass spectrometry. While 

these prototype instruments mark an important step towards a fieldable MS instrument, these 

systems are not constructed or ruggedized to allow constant operation in harsh environments. 

Recently, Flir Systems, Inc. has developed a field-ready mass spectrometer (AI-MS 1.2) 

featuring an atmospheric ion inlet, marking the development of the first high performance 

instrument of this kind.19 Technologies like Flir Systems AI-MS 1.2 becoming commercial 

products is important in terms of availability and applicability to practitioners of this technology. 

1.2.4 Ambient Mass Spectrometry 

Ambient mass spectrometric methods, a topic of much interest in analytical chemistry 

today, have allowed the analysis of “ordinary” samples in their native environment with little or 

no sample preparation, different from traditional analytical methods that require extensive 

sample preparation and/or introduction of sample into an instrumental vacuum system before 

ionization. Electrospray ionization,20 for which John Fenn was awarded the Nobel Prize in 

Chemistry in 2002, readily allows the analysis of chemical species in solution, revolutionizing 

the analysis of biological macromolecules. Techniques such as atmospheric pressure chemical 

ionization (APCI) have allowed rapid analysis of volatile and semi-volatile chemical species in 

complex gas matrices without preconcentration.21,22 While these techniques allow analysis of 

liquid and gaseous samples, the ability to directly detect surface-bound analyte from native 

samples had been lacking until recently. 

Desorption electrospray ionization (DESI), the first reported ambient MS method, allows 

ions to be created directly from surfaces under ambient conditions and then collected and 

analyzed by MS systems equipped with an atmospheric pressure inlet.23 DESI has been reported 

for the analysis of solid and liquid chemical species of forensic interest with little or no sample 

preparation,24-27 while exploiting the inherent advantage of sensitivity afforded by MS and the 

specificity of tandem mass spectrometric analysis. DESI is carried out by directing charged 

microdroplets generated by an electrospray of appropriate solvent (typically methanol/water) 

onto a contaminated surface or solid analyte, as seen in Figure 1-1. Neutral analytes present on 

the surface are then desorbed under ambient conditions as secondary ions and detected almost 

instantaneously through a capillary inlet. DESI mass spectra are similar to typical ESI mass 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
4

spectra in that they are dominated by the protonated 

molecular ion [M + H]+ of analytes of interest and other 

simple adducts with little molecular fragmentation. 

The versatile nature of DESI-MS has made it an 

attractive alternative for forensic applications, as recently 

reviewed.28 Forensic applications reported in literature 

include direct analysis of cannabis,29 determination of 

counterfeit pharmaceuticals,30 analysis of latent 

fingerprints for suspect identification31 and for chemical 

residues,32 direct analysis of clothing for drugs of abuse and explosives residues,33 and analysis 

of gunshot residue.34 Substrates analyzed by DESI-MS include glass, plastics, metals, stone, 

cloth, skin, and vegetation, and this list continues to grow. The rapid, direct analysis afforded by 

DESI-MS opens up new avenues of forensic analysis, and many new types of evidence could be 

potentially screened for relevance. 

Other reported ambient MS techniques have high potential in regards to forensic sample 

analysis, such as low temperature plasma mass spectrometry (LTP-MS).35 In LTP-MS, depicted 

in Figure 1.2, an ambient plasma is generated by a dielectric barrier (i.e. glass) discharge in the 

presence of either nitrogen or helium at atmospheric pressure. The generated plasma can 

desorb/ionize surface-bound chemicals, yielding data very similar to that obtained by DESI-MS, 

but without the need for solvent. Recently introduced paper spray ionization (PSI) touts the 

ability to turn physical transfer swabs commonly employed in forensic investigations directly 

into disposable ionization sources.36 PSI-MS works by combining two mechanisms, paper 

chromatographic separation and electrospraying. After a chemical is applied to the paper 

triangle, the combination of added solvent (a flexible variable) and high voltage allows the now 

dissolved analyte to migrate through the paper medium, eventually coming to the terminal point 

of the triangle (as seen in Figure 1.3). The build-up at this point generates a stable electrospray 

of charged droplets, which contain the added solvent and deposited analyte, that then go on to 

desolvate and generate dry, gas-phase analyte ions that are detected by the MS. PSI has two 

distinct advantages towards potential field usage. First, PSI is marked by extreme simplicity in 

setup and operation. Second, besides depositing a pre-dissolved sample onto the paper triangle 

for PSI analysis, the paper itself can be used as a surface swab, effectively sampling large areas. 

Figure 1-2. Schematic of LTP-MS ionization source, 

utilizing an ambient plasma to desorb/ionize surfacebound analytes (reproduced from Ref. 35)

Figure 1-3. Representation of PSI-MS analysis 

directly from a paper triangle containing 

analyte.

Discharge Gas

~0.4 L/min

3kVpp

2.5 kHz

1W

Atmospheric Inlet of

Mass Spectrometer

Sample

LTP

Desorbed Ions

Grounded 

Electrode

HV Electrode

Dielectric 

Barrier

Surface

a) b)

30° C

Solvent

MS Inlet

Figure 1-1. Schematic of the 

experimental setup for DESI-MS, 

allowing chemical analysis of 

untreated surfaces. 

Solvent

Analyte/Surface

MS Inlet

N2

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
5

1.3 Rationale for the Research 

In an effort to fulfill the current technological needs of forensic science practitioners and 

associated laboratories, we sought to create a broadly-applicable, portable chemical detector 

based on a state-of-the-art mass spectrometer (MS) capable of sampling externally-generated 

ions. Utilizing the Flir Systems AI-MS 1.2 portable instrument as a testbed, several conventional 

and ambient ionization techniques were created and/or validated for coupling to the system to 

allow screening of solid, liquid, and gas-phase chemicals of forensic interest. Application of 

ambient ionization techniques coupled to this portable system towards complex samples (i.e.

bulk powders, chemical residues in latent fingerprints, pharmaceutical tablets, clandestine 

synthetic reaction products/apparatus etc.), authentic evidentiary seizures, and emerging threats 

was of increased interest to show feasibility in field implementation. Development of swabbased physical transfer methods extended to this instrumentation was intended to provide 

flexibility in analyzing geometrically-complex samples and large surface areas. Demonstrating 

congruency of both MS and MS/MS data collected on the Flir AI-MS 1.2 to that obtained on labscale, commercial instrumentation was important in showing potential for adoption as an 

accepted technique in crime scene investigation and forensic analyses. 

The principal scientific questions that were addressed in order to gauge performance of 

the proposed technology included: (i) can a portable mass spectrometer be adapted to allow 

direct analysis of solid, liquid, and gas-phase chemical species? (ii) can evidence be effectively 

screened in a non-destructive nature? (iii) is physical transfer of chemical residues more effective 

than direct surface analysis? (iv) is the developed technology on par with current methods in 

terms of reliability, reproducibility, selectivity, and sensitivity? (v) is this technology robust in 

terms of the current and changing needs of forensic science and law enforcement personnel? 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
6

2. Methods 

NOTE: This section serves to provide operating conditions and associated variables for projectrelated methods. As method development was a critical aspect of this project, expanded detail 

for several topics is provided in Section 3 – Results. 

2.1 Instrumentation and Ionization Sources 

2.1.1 Flir Systems AI-MS 1.2 

All investigations into ambient MS utilized a Flir Systems AI-MS 1.2 (Flir Mass 

Spectrometry, West Lafayette, IN, USA), a portable, cylindrical ion trap (CIT) mass 

spectrometer that has been ruggedized for field usage. This portable system allows sampling of 

externally-generated ions via a capillary-based atmospheric pressure inlet, and analyte 

confirmation is possible via tandem MS (MS/MS). All AC/DC voltages needed for instrument 

operation and spray-based ionization (i.e. ESI, DESI and PSI) are incorporated, as well as an onboard helium supply for the CIT damping gas needed for MS/MS fragmentation. Nebulizing gas 

(N2 or air) necessary for DESI analysis is supplied by a stand-alone tank, allowing the use of 

small, self-contained breathing apparatus (SCBA) tanks commonly utilized by the first response 

community for field implementation. The size (24” x 20” x 15”, L x W x H), weight (98 lbs.) 

and ruggedness of this instrument makes it an amenable platform for field-based, CSI 

applications. In selecting appropriate ionization sources to implement on the AI-MS 1.2 testbed, 

only those that were relatively small in size and could operate without the need of bulky external 

power supplies were chosen; these selection criteria eliminated other ambient techniques that 

have shown promise in forensic analysis, but are not quite field-ready (e.g. direct analysis is real 

time, or DART28).

2.1.2 MS and MS/MS Analysis 

MS analysis on the Flir Systems AI-MS 1.2 was typically performed with a 70 to 450 m/z 

range for DESI, ESI, and PSI experiments. General data collection utilized an average of 5 

scans/spectrum. APCI experiments utilized a 50 to 450 m/z range due to the lower molecular 

weights of the volatile compounds analyzed. MS/MS analysis utilized the same m/z ranges as in 

MS analysis. Multiple settings for MS/MS analysis were available for adjustment, including the 

precursor ion isolation window, frequency of the AC dissociation waveform applied, collision 

energy (i.e. the energy imparted to isolated ions via collision-induced dissociation, CID, with 

helium damping gas), and dissociation time. These values were initially set to ±10 m/z, 173.5 

kHz, an instrument-calculated value based on analyte m/z value, and 15 ms respectively, and 

were then systematically optimized for each individual analyte. 

2.1.3 ESI and DESI 

ESI and DESI experiments utilized an on-board ESI/DESI ionization assembly that fixed 

a 55° spray angle and spray emitter tip-to-analysis surface distance; this source is described in 

detail in Section 3.1.1. Operating conditions for ESI and DESI included a 4 kV spray voltage, 

100 PSI nebulizing gas pressure (N2), and 3 (DESI) or 10 (ESI) μl/minute solvent flow rate. 

During field use, the N2 nebulizing gas tank is replaced with a small SCBA tank filled with 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
7

OSHA D breathable air. Positive-mode operation utilized a 1:1 methanol:water with 0.1 % 

formic acid spray solvent, and negative-mode operation generally utilized a 1:1 methanol:water 

spray solvent. Selected experiments utilized a home-built, positionable DESI source constructed 

of a fused silica capillary held within a 1⁄4 inch stainless steel Swagelok tee with nebulizing gas 

supplied axially, pictured in Figure 2-1. 

2.1.4 LTP 

LTP ionization utilized a home-built source 

constructed using a stock nanoESI holder with a gas 

assistance port (Warner Instruments, ESW-M15P) for 

the LTP probe and operated with helium gas flowed at 

a rate of 0.2-0.3 L/min. Voltages of 3-4 kV were 

provided by a commercially-available power supply 

(Information Unlimited, PVM500), operated with a 

33.6 kHz AC signal needed for plasma generation. The 

electrode of the nanoESI probe was grounded and 

sheathed within a quartz capillary (Sutter Instruments) 

that was wrapped with a small section of adhesivebacked copper tape and connected to the LTP power 

supply to create a dielectric barrier. A schematic of 

this source is provided in Section 3.1.1.

2.1.5 PSI 

PSI ionization utilized paper triangles pre-cut into 10 mm by 5 mm isosceles triangles 

from Whatman chromatography paper (Fisher Scientific, Inc., Hampton NH, USA). After 

analyte is transferred to the paper, it is allowed to dry and attached to a toothless “alligator clip”-

style electrode connected to the instrument’s high voltage supply. After application of 1.7 μl of 

appropriate spray solvent and 4 kV, a stable electrospray can be generated from the paper 

substrate. Further, the paper triangle can be utilized as a surface transfer swab by pre-wetting 

with 2.0 μL of methanol prior to probing the substrate of interest. 

2.1.6 APCI 

APCI ionization utilized tungsten discharge needles under 10 MΩ resistance to generate a 

corona discharge after application of 4 kV through the high voltage supply of the Flir AI-MS 1.2. 

The entire discharge needle assembly was housed within a chemically-resistant source body 

possessing inlet and outlet ports for sample introduction and removal of exhausted vapors that 

could otherwise lead to a buildup of backpressure in the source, as illustrated in Figure 2-2 with 

one iteration of our source design. A length of chemically-resistant, perfluoroalkoxy alkanes 

(PFA) tubing was attached to the inlet port to enable non-proximate sampling, and it possessed a 

removable Swagelok tee fitted with a rubber septum to serve as in injection port to facilitate 

introduction of headspace samples through Hamilton Gastight syringes. A small diaphragm 

pump (KNF Neuberger UNMP015M) powered by an AC adapter and connected to the exhaust 

port via PFA tubing was utilized to continually draw fresh sample vapors through the sampling 

tube into the discharge region for ionization, past the inlet capillary for intake of ions into the 

Figure 2-1. Home-built, position-flexible 

DESI source. A Swagelok tee assembly 

houses fused silica capillaries for solvent 

flow and nebulizing gas.

Solvent Flow

Gas Flow

Emitter Tip

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8

instrument, and then out through the exhaust port. The source body attached directly over the 

inlet capillary of the instrument with a compression fitting. 

Figure 2-2. Basic design and usage of an APCI source to sample volatile 

chemical signatures from ambient air. An auxiliary pump continually draws 

fresh sample vapor through chemically-resistant PFA tubing into the corona 

discharge region. Resulting ions enter the MS inlet while the pump evacuates

used sample through an exhaust port. 

2.1.7 GC-MS

GC-MS analysis was performed with a Thermo ITQ 1100, and was utilized only for 

assessment of transfer and extraction efficiencies of transfer swabs, detailed in Section 3.2.1. 

Prepared and extracted samples were spiked with controlled amounts of internal standard (d3-

methamphetamine) and injected via autosampler for analyses. The temperature profile 

implemented had at an initial temperature of 50°C held for 0.50 minutes, ramped to 200°C at a 

60°C/minute rate, and then raised to the 290°C final temperature at 30°C/minute. Calibration 

curves were then generated using a minimum of three replicates for standard solutions, and all 

swabs investigated were analyzed using a minimum of five replicates. 

2.2 Sample Preparation 

2.2.1 Standards and Liquid-Phase Samples 

For characterization studies, stock analytical standards of multiple drugs of abuse, 

pharmaceuticals, and synthetic precursors were purchased from Cerilliant Co. (Round Rock, TX, 

USA) in 1000 ppm (1.0 mg/mL) concentrations. Serial dilution of the stock solutions was then 

performed using analyte appropriate solvents, including methanol and acetonitrile purchased 

from Fisher Scientific (Pittsburg PA) at HPLC grade. DESI and PSI analysis primarily utilized 

MS Inlet

Corona

Discharge

Flow of 

Volatile Species/Headspace

Samples of Interest

Auxiliary

Pump Exhaust

HV 

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100 ppm dilutions, and ESI utilized dilutions ranging in 0.1 to 10 ppm concentrations depending 

on the ionization efficiency of individual analytes. Selected unrestricted substances with forensic 

relevance as potential cutting agents or impurities from clandestine syntheses were purchased as 

bulk powders from Sigma-Aldrich Co. (St Louis, MO, USA). Appropriate masses of powder 

were then dissolved in methanol using a volumetric flask to produce a 1000 ppm stock solution 

used for serial dilutions. 

Samples for direct presentation to the DESI source were prepared by using adjustable 

pipets to spot 1 μL aliquots of a standard solution upon printed Teflon slides (Prosolia Inc., 

Indianapolis, IN) or upon a surface of interest to deposit a known mass of analyte. The solvent 

was then allowed to fully evaporate before the substrate itself was positioned in the DESI spray 

region. Samples for indirect presentation using transfer swabs were prepared in a similar fashion. 

Samples for PSI-MS analysis were prepared by spotting aliquots of 2.0 μL or less directly upon 

the paper triangle substrate itself and allowing it to dry before application of spray solvent. For 

indirect application of the analyte, the paper triangle was wetted with 2.0 μL of methanol and 

used to swab a surface of interest in a circular motion. The paper triangle was then allowed to 

dry and analyzed using similar methodology. 

2.2.2 Solid-Phase Samples and Powders 

Powder samples were prepared from bulk powders purchased from Sigma-Aldrich Co. 

(St Louis, MO, USA), pharmaceutical tablets purchased from local retailers ground into a 

powder with a mortar and pestle, or from seized evidentiary materials obtained through 

collaboration with law enforcement. A small mass of powder, typically ~ 1 mg, was placed upon 

a surface of interest using a clean spatula. DESI analysis of powder samples used either transfer 

swabs or adhesive-backed glass slides to hold and present the powder to the spray region. For 

slide preparation, a gentle stream of canned air was applied to remove any loose powder that 

may otherwise be transferred into the inlet capillary of the instrument during presentation to the 

DESI source and cause carryover. For transfer swabs, a spatula was first used to separate the 

powder into small portions. A swab wetted with a variable amount of methanol (see Section 

3.2.2) was used to sample the powder and then presented using a positioning guide for direct 

analysis. For PSI analysis of powder samples, a paper triangle was wetted with 2.0 μL of 

methanol prior to sampling the powder, followed by direct analysis of the paper substrate. 

2.2.3 Gas-Phase Samples 

Gas-phase samples for APCI analysis were prepared by enclosing small liquid volumes 

of volatile chemicals of interest in flasks sealed with rubber septa. The flasks were set aside to 

allow headspace vapors to build up and reach equilibrium to allow determination of gas-phase 

concentrations via the analytes partial pressure. An aliquot of this headspace is sampled with a 

Gastight syringe (Hamilton Co., Reno, NV) and accurately flowed via Harvard Apparatus 

syringe pump into a calibrated flow of room air (for these studies, 5 L/min). This diluted air 

sample (now containing a known amount of accelerant vapor) can then be flowed directly into 

the custom APCI source constructed for the Flir AI-MS 1.2. Analysis of undiluted vapor was 

performed by positioning the inlet of the sampling tube near bulk liquids or objects releasing 

gaseous vapors, taking care to avoid direct contact with the object or liquid to prevent coating the 

sampling tube with the material in question, which could lead to saturating the instrument 

detector or carryover. 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

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10

To simulate the direct analysis of evidence that may be present at an actual arson 

investigation, representative charred samples were prepared by ignition with potential 

accelerants. Initial testing involved exposing 1 in. x 1 in. x 0.25 in. pinewood blocks with small 

quantities (~5 mL) of a potential liquid accelerant and igniting it in a glass petri dish. The wood 

sample was then ignited and allowed to openly burn until all accelerant liquid was exhausted, 

and the block was allowed to become visibly charred before being capped to extinguish any 

remaining flames. Charred samples were then placed in Erlenmeyer flasks sealed with rubber 

septa for transport and to allow generation of headspace vapor within. These headspace vapors 

were then analyzed by APCI after transporting them via a pump-assisted sampling tube (shown 

in Figure 2-2) into the ionization source. 

2.3 Analytical Characterization 

2.3.1 Spectral Quality and Accuracy 

 MS and MS/MS spectral quality was assessed by comparison of both the intensity and 

breadth of ions (i.e. molecular ion signatures in base MS mode and fragment ions seen in 

MS/MS with relative abundances) to data collected on lab-scale, commercial MS systems 

utilizing similar ionization methods and by that reported in chemical literature. While some 

deviation in the population and abundances of fragment ions were seen, they were overall 

congruent with all direct comparisons; MS/MS yields are very much effected by both the 

fragmentation method (e.g. CID) and mass analyzer employed. 

Accuracy of spectral data obtained with the Flir AI-MS 1.2 was verified by comparison 

with that obtained in the Wiley Registry® of Tandem Mass Spectral Data (MSforID) through 

collaboration with Dr. Herbert Oberacher (Associate Professor, Innsbruck Medical University, 

Austria). Blind MS/MS spectra generated with the AI-MS 1.2 utilizing three separate collision 

energies for each analyte were submitted to the MSforID spectral database to calculate “relative 

average match probability,” or ramp value; the searching algorithm of the MSforID database has 

been reported in detail in literature.37 Single ramp-values range between 0 and 100, and a high 

compound-specific ramp value (40 or higher) indicates high similarity between the unknown and 

the reference compound. The database identifies the submitted chemical data as the entry that 

produces the highest ramp value. More detailed information regarding these assessments can be 

found in Section 3.1.7.

2.3.2 Limits of Detection and Quantitation 

Limits of detection (LODs) were determined for all examined ionization methods in 

MS/MS mode by measuring signal responses from purchased analytical standards and utilizing 

the traditional threshold of a signal-to-noise ratio of 3 (i.e. signal intensity corresponding to the 

analyte being three times higher than the standard deviation of the mass spectral noise level). In 

instances where there was no appreciable noise level in MS/MS analysis, the LOD was 

determined as the quantity of analyte that gave lowest fragment ion signal that was both stable 

and detectable. 

To determine detection limit of APCI analysis on the Flir AI-MS 1.2, defined as a signalto-noise ratio of 3, accurate concentration gas standards were produced and analyzed. To create 

these known standards, equilibrated headspace was taken from sealed flasks containing liquid 

accelerant at standard temperature and pressure. As the vapor pressure is a known variable for 

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11

most of the common accelerants (accessed from the Stanford University SRC Physical Properties 

Database – PHYSPROP), the corresponding gas-phase concentration (in parts per million [ppm]) 

can be calculated from the headspace. A known volume of this headspace is sampled with a 

Hamilton Gas-Tight syringe and accurately flowed via Harvard Apparatus syringe pump into a 

calibrated flow of room air (for these studies, 5 L/min). This diluted air sample (now containing 

a known amount of accelerant vapor) is then flowed directly into the constructed APCI source of 

the Flir AI-MS 1.2. 

Quantitative ability was assessed by constructing calibration curves for select drugs of 

abuse using DESI-MS. To construct these curves, standard solutions of each analyte were 

spotted onto glass substrates to reach the target deposited mass. The average of four replicate 

measurements of direct DESI analysis intensity was used for plotting purposes. Linear dynamic 

range and precision could then be assessed. 

2.3.3 Reliability (False Positive/False Negative Rates) 

Reliability was assessed by calculating false positive/false negative rates for a large 

quantity of control samples (i.e. “positive” samples where a known chemical residue was present 

and “negative” samples with no residue). Analysis of these controls was completed over a one 

month period at different times of day in an effort to determine inter- and intraday variability in 

collected spectral intensity for all positive controls. 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

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12

3. Results 

The overall project was separated into seven discrete tasks in order to determine performance 

and breadth of applicability of ambient ionization methods coupled to the Flir Systems AI-MS 

1.2 portable mass spectrometer, as delineated below. 

3.1 Task 1: Test Proof of Concept Detection of Chemicals of Interest on the Flir 

Systems AI-MS 1.2 

The Flir Systems AI-MS 1.2 is a portable, cylindrical ion trap (CIT) mass spectrometer 

that has been ruggedized for field usage. This portable system allows sampling of externallygenerated ions via a capillary-based atmospheric pressure inlet, and analyte confirmation is 

possible via tandem MS (MS/MS). All AC/DC voltages needed for instrument operation and 

desorption electrospray ionization (DESI) are incorporated, as well as an on-board helium supply 

for the CIT damping gas needed for MS/MS fragmentation. Nebulizing gas (N2 or air) necessary 

for DESI analysis is supplied by a stand-alone tank, allowing the use of small, self-contained 

breathing apparatus (SCBA) tanks commonly utilized by the first response community for field 

implementation. The size (24” x 20” x 15”, L x W x H), weight (98 lbs.) and ruggedness of this 

instrument makes it an amenable platform for field-based, CSI applications. A photo of the 

testbed instrument can be seen in Figure 3-1a. 

3.1.1 Compatible Ionization Sources for Solid and/or Liquid-Phase Samples 

 Over the course of the project, several conventional and ambient ionization methods were 

shown applicable on the Flir Systems AI-MS 1.2 system, including electrospray ionization (ESI), 

desorption electrospray ionization (DESI), and, to a lesser extent, low temperature plasma (LTP) 

and paper spray ionization (PSI). The AI-MS 1.2 system (Figure 3-1a) has a position-stationary 

ionization assembly that allows the use of ESI-MS for solution-based analytes and DESI-MS for 

solids and surface-bound residues (See Figure 3-1b). The stationary source is mounted to fix 

both the DESI spray angle (55°) and DESI emitter tip-to-analysis surface distance. The DESI 

sprayer is held in a hemispherical enclosure, and once relatively-flat samples are placed at the 

enclosure egress, they undergo desorption/ionization. A depiction of this enclosure is seen in 

Figure 3-2a, with a photo depicting the direct analysis of a glass side with DESI seen in Figure 3-

2b.

Figure 3-1a. Photo of Flir Griffin AI-MS 

instrument, with aluminum can in place for scale.

Figure 3-1b. Stock ionization assembly that allows both ESI 

(solution-based analytes) and DESI (surface-based analytes)

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13

Figure 3-2a. Depiction of swab analysis using DESI. Charged 

droplets impinge upon the swab surface, desorbing/ionizing 

analytes present and projecting them toward the MS capillary 

inlet for mass analysis. Courtesy of Flir Mass Spectrometry.

Figure 3-2b. Photo depicting direct analysis of 

a Teflon-coated glass microscope slide. Upon 

placement in the DESI spray, surface-bound 

analytes are instantaneously ionized and 

detected with minimal carryover

 To facilitate the analysis of more geometricallycomplex samples (i.e. those that require flexibility in 

positioning), a position-adjustable DESI source was 

constructed in-house using a 1⁄4” stainless steel Swagelok tee 

and fused-silica capillaries for solvent flow and axial 

nebulizing gas (Figure 3-2c). Positioning of this source 

relative to both the sample surface and capillary inlet of the 

MS allows direct analysis of a variety of substrates of 

forensic interest, including pill bottles and plastic baggies 

(discussed later in this report). While demonstrated as 

useful to certain samples, the position-adjustable DESI 

source has significant disadvantages for field usage 

compared to the stationary ESI/DESI assembly. As the 

DESI spray angle and DESI emitter tip-to-analysis surface 

distance must be set and maintained by the operator with the custom source, there is a greater 

potential for misuse compared to the factory spray assembly. Enclosing the spray emitter (as in 

the factory spray assembly) also protects from breakage and contamination when samples are 

introduced. The use of surface swabbing as a means to investigate residues from geometricallycomplex or large area samples and sub-sample bulk powders was extensively investigated during 

this project (discussed further in Section 3.2). Used swabs can then be presented directly into the 

ESI/DESI spray assembly to detect and identify transferred compounds, as depicted in Figure 3-

2a. DESI-MS was determined to be an ambient ionization method of high flexibility and utility, 

making it the focus of much of the research and spectral databasing efforts herein. 

A custom-built, low temperature plasma (LTP) ionization source (see Figure 3-4) was 

constructed and implemented for proof-of-principle testing on the Flir AI-MS 1.2, as it has been 

recently shown able to detect surface-bound explosive residues using metastable helium species 

produced in a dielectric barrier discharge The LTP probe was produced using a stock nanoESI 

holder with gas assistance port (Warner Instruments, ESW-M15P), through which helium gas 

was flowed at a rate of 0.2-0.3 L/min. To provide the necessary dielectric barrier, a quartz 

capillary (Sutter Instruments) was sheathed over the electrode of the nanoESI probe (grounded), 

Figure 3-2c. Photo of the home-built 

DESI source, composed of a Swagelok 

tee assembly and fused silica capillaries 

for solvent flow and nebulizing gas.

Gas Flow

Emitter Tip

Solvent Flow

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to which a small section of adhesive-backed copper tape was wrapped and connected to the LTP 

power supply. When AC voltage is applied to the copper tape, a plasma discharge region is 

produced on the inside of the capillary due to the dielectric medium; this discharge produces 

energetic He species that go on to directly or 

indirectly (through production of secondary reagent 

ions) ionize surface-bound analytes. A 

commercially-available power supply was utilized for 

this source (Information Unlimited, PVM500), 

producing the 3-4 kV, 33.6 kHz AC signal needed for 

plasma generation. LTP-MS was examined toward 

explosives analysis, but was determined to be a suboptimal solution when compared to the ruggedness 

and reliability of the stationary ESI/DESI assembly. 

While not a main focus of the initial project 

proposal, paper spray ionization (PSI) was also 

investigated for use with the Flir AI-MS 1.2 system, 

as it offers a cost-effective analysis method coupled 

with surface swabbing capability. Generated mass 

spectra are very similar to that obtained with both ESI 

and DESI-MS on this instrument. 

Figure 3-4. Depiction of paper spray ionization 

directly from a paper triangle containing 

analyte. By application of appropriate solvent 

and high voltage, deposited or swabbed 

analytes on the paper can be directly 

ionized/detected with the Flir Systems AI-MS.

Figure 3-5. Photo of the PSI source in use on the Flir 

AI-MS system. The red cable serves dual purposes of 

holding the paper substrate in place and delivering the 

required high voltage for ionization.

PSI-MS works by combining two mechanisms, paper chromatographic separation and 

electrospraying. After a chemical is applied to the paper triangle, the combination of added 

solvent (a flexible variable) and ~ 4 kV of high voltage allows the dissolved analyte to migrate 

through the paper medium, eventually coming to the terminal point of the triangle (as seen in 

Solvent

MS Inlet

Figure 3-3. Depiction of the home-built 

LTP source. A discharge is produced 

between a (A) grounded electrode and (C) 

high voltage outer electrode, with a (B) 

quartz glass capillary serving as the 

dielectric barrier needed and ionization 

probe. The excited gas species produced 

can desorb/ionize surface-bound samples 

for MS analysis.

MS Inlet

Surface/Sample

A

He(g) B

C

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15

Figure 3.4). The build-up at this point generates a stable electrospray of charged droplets, which 

contain the added solvent and deposited analyte, that then go on to desolvate and generate dry, 

gas-phase analyte ions that are detected by the MS. PSI has two distinct advantages towards 

potential field usage. First, PSI is marked by extreme simplicity in setup and operation. As seen 

in the photo in Figure 3-4, the only materials needed to perform these analyses that are not 

supplied by the Flir AI-MS 1.2 is the paper substrate itself and the delivered solvent; the onboard high voltage “alligator clip” cable delivers the needed electrospray voltage and holds the 

paper substrate in place. Second, besides depositing a pre-dissolved sample onto the paper 

triangle for PSI analysis, the paper itself can be used as a surface swab, effectively sampling 

large areas. This ability aligns itself well with goals of Task 2: Investigate Alternative Surface 

Sampling Methodologies, as it has the potential to eliminate the extra steps needed for DESI-MS 

analysis of utilized sampling swab. For PSI, the surface swab and ionization source are 

effectively the same. 

3.1.2 Data Quality and Broad Application to Forensic Chemical Analysis 

Ambient ionization coupled with the Flir AI-MS 1.2 system has far exceeded our initial 

expectations in regards to performance and applicability to analytes and samples of interest to 

forensic science and crime scene investigation. At the time of writing, our database of detected 

and confirmed analytes utilizing the AI-MS 1.2 numbers 73 and continues to grow as new and 

emerging illicits continue to be added. This spectral database contains MS and MS/MS from a 

wide array of illicit drugs, abused pharmaceuticals, potential cutting agents, explosives and 

species related to ballistics, and accelerants, and representative mass spectra for these 

compounds can be seen in Appendices A and B. Tabulated MS and MS/MS information, 

including optimized MS/MS method conditions for each analyte and observed ion 

fragmentations, can be seen in Table 3-1. 

For the analytes listed, all non-volatile species were analyzed at a deposited mass of 100 

ng via DESI-MS, the milestone amount targeted for this grantwork, unless they were directly 

analyzed via atmospheric pressure chemical ionization (APCI, see Section 3.3) due to volatility. 

Analytes specifically confirmed via APCI are known accelerants or chemical warfare agent 

simulants and are indicated as such. Of note, a majority of the compounds tested produced very 

high spectral signal intensity even at 100 ng, meaning that most limits of detection for these 

species lie in the very low to sub-ng range. Target analytes can also be detected and identified in 

complex matrices and authentic forensic evidence, as discussed in Sections 3.5 and 3.6. 

Furthermore, spectral data collected on the AI-MS 1.2 was highly congruent in regards to both 

MS and MS/MS ion signatures collected on lab-scale MS instrumentation and also seen in 

scientific literature; this is seen as a major benefit towards actual implementation in CSI 

applications and potential acceptance as a validated method. 

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16

Table 3-1. MS and MS/MS Characterization of Project Analytes on the Flir Systems AI-MS 1.2 

Compound MW (Da) Precursor Ion 

(m/z)

MS/MS 

Transitions

(m/z)

**

Frequency 

(KHz)

Voltage 

(V)

Time 

(ms)

Acetaminophen 151.06 152 [M+H]+

152 (39%)

175.5 0.230 15.0

110 (100%)

Acetone† 58.08

59 [M + H]+

N/A N/A N/A N/A

117 [2M + H]+

Alprazolam 308.77 309 [M + H]+

281 (100%)

172.5 0.370 22.0

274 (62%)

241 (19%)

206 (20%)

165 (6%)

Amobarbital 226.27 225 [M – H]-

182 (100%) 168.5 0.280 30.0

Amphetamine 135.2 136 [M + H]+

119 (100%)

175.0 0.195 22.5

91 (18%)

Benzene† 78.11 79 [M + H]+ N/A N/A N/A N/A

Benzocaine 165.19 166 [M + H]+

138 (100%)

120 (14%) 174.0 0.235 15.0

93 (2%)

Benzoylecogonine 289.33 290 [M + H]+

168 (100%) 171.0 0.275 15.5

Caffeine 194.19 195 [M + H]+

138 (100%) 173.0 0.340 19.5

Chlorodiazepoxide 299.75 300 [M + H]+

283 (100%)

172.0 0.360 9.0

241 (23%)

Cocaethylene 317.38 318 [M + H]+

196 (100%)

174.0 0.455 15.0

150 (11%)

Cocaine

303.35 304 [M + H]+182 (100%)

172.5 0.280 13.5

150 (7%)

Codeine 299.36 300 [M + H]+

282 (11%)

172.5 0.410 16.0

243 (17%)

225 (22%)

215 (100%)

183 (23%)

161 (14%)

Creatine 131.13 132 [M + H]+

90 (100%) 174.5 0.200 10.5

Desomorphine 271.35 272 [M + H]+

215 (100%)

172.5 0.335 22.0

197 (16%)

Dextromethorphan 271.43 272 [M + H]+

215 (100%)

171.5 0.405 15.0

213 (23%)

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17

147 (27%)

Diazepam 284.74 285 [M + H]+

257 (92%)

173.0 0.390 13.5

228 (25%)

222 (100%)

193 (28%)

182 (28%)

154 (83%)

105 (15%)

Dimethyl 

Methylphosphonate† 124.08 125 [M + H]+

125 (25%)

111 (100%) TBD TBD TBD

93 (15%)

Dimethyl Phthalate 194.18 195 [M + H]+

163 (100%) 173.0 0.255 14.0

1,3-Dinitrobenzene 168.11 168 [M]-. TBD N/A N/A N/A

2,4-Dinitrotoluene 182.13 181 [M – H]- TBD N/A N/A N/A

Diphenylamine 169.23 170 [M + H]+

92 (100%) 173.5 0.300 15.0

Ecgonine Methyl Ester 199.25 200 [M + H]+

182 (100%) 173.5 0.255 15.5

Ephedrine 165.23 166 [M + H]+

148 (100%) TBD TBD TBD

Ethanol† 46.07

93 [2M + H]+

N/A N/A N/A N/A

139 [3M + H]+

Ethyl Centralite 268.35 269 [M + H]+

148 (100%)

170.0 0.250 16.0

120 (76%)

Ethyl Ether† 74.12

75 [M + H]+

N/A N/A N/A N/A

149 [2M + H]+

Fentanyl 336.47 337 [M + H]+

188 (100%) 171.5 0.375 14.0

Flunitrazepam 313.27 314 [M + H]+

300 (94%)

173.0 0.380 17.5

286 (75%)

268 (100%)

240 (34%)

Guaifenesin 198.09 199 [M+H]+

181 (23%)

TBD TBD TBD 163 (81%)

151 (17%)

125 (100%)

Heroin 369.41 370 [M + H]+

328 (70%)

310 (30%) 172.0 0.485 16.0

268 (100%)

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237 (14%)

211 (27%)

Hydrocodone 299.37 300 [M + H]+

243 (22%)

173.5 0.420 17.5

225 (9%)

199 (100%)

183 (16%)

Hydromorphone 285.14 286 [M + H]+

243 (4%)

172.5 0.350 14.5

229 (16%)

211 (21%)

185 (100%)

Hydroxyzine 374.9 375 [M + H]+

201 (100%)

171.0 0.315 15.0

166 (21%)

Isopropanol† 60.1

61 [M + H]+

N/A N/A N/A N/A

121 [2M + H]+

Kerosene Various Various N/A N/A N/A N/A

Ketamine 237.73 238 [M + H]+

220 (100%)

208 (32%) 172.5 0.430 16.5

152 (21%)

Levamisole 204.29 205 [M + H]+

178 (100%)

145 (45%) 173.0 0.275 15.0

88 (20%)

Lidocaine 234.34 235 [M + H]+

85 (100%) 171.5 0.275 14.5

Lorazepam 320.2 321 [M + H]+

303 (69%)

172.5 0.385 18.5

275 (100%)

LSD 323.43 324 [M + H]+

281 (53%)

223 (100%) 172.0 0.430 20.0

197 (26%)

MDMA 193.25 194 [M + H]+

163 (100%) 171.5 0.160 18.5

MDPV 275.34 276 [M + H]+

205 (95%)

171.5 0.255 14.0

175 (100%)

135 (31%)

126 (21%)

Mephedrone 177.24 178 [M + H]+

160 (100%)

TBD TBD TBD

147 (6%)

Mescaline 211.26 212 [M + H]

+

195 (195%) 173.5 0.260 14.0

Methadone 309.45 310 [M + H]+

265 (100%) 171.0 0.345 12.5

Methamphetamine 149.23 150 [M + H]+

119 (100%)

174.5 0.180 15.0

91 (23%)

Methanol† 32.04 65[2M + H]+ N/A N/A N/A N/A

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97[3M + H]+

Methyl Centralite 240.3 241[M + H]+

134 (100%) 172.5 0.315 13.0

Methyl ethyl ketone† 72.11

73 [M + H]+

N/A N/A N/A N/A

145 [2M + H]+

Methyl salicylate† 152.15

153 [M + H]+

121 [MH – 121 (100%) TBD TBD TBD

CH3OH]+

Methylone 207.23 208 [M + H]+

190 (100%)

TBD TBD TBD

160 (96%)

Methylphenidate 233.3 234 [M + H]+

84 (100%) 173.0 0.250 4.0

Morphine 285.34 286 [M + H]+

268 (11%)

172.5 0.375 15.0

229 (28%)

211 (32%)

201 (100%)

183 (37%)

173 (29%)

155 (12%)

Oxycodone 315.36 316 [M + H]+

298 (100%) 172.0 0.315 15.0

4-nitro diphenylamine 214.22 215 [M + H]+

198 (100%) 172.5 0.275 11.0

N-nitroso diphenylamine 198.22 199 [M + H]+

169 (100%) 173.0 0.475 15.0

PCP 243.39 244 [M + H]+

159 (100%)

173.0 0.290 13.0

86 (83%)

Pentedrone 191.27 192 [M + H]+

174 (100%)

161 (10%) 172.5 0.265 17.0

132 (31%)

Pentobarbitol 226.27 225 [M – H]-

182 (100%) 168.5 0.280 30.0

Phenacetin 179.22 180 [M + H]+

138 (100%)

173.5 0.215 13.0

110 (23%)

Phenobarbitol 232.24 231 [M – H]-

188 (100%) 168.5 0.280 30.0

Phenylephrine 167.09 168 [M+H]+

150 (100%)

172.5 0.290 15.0

135 (10%)

Phenylephrine In-Source 

Fragment (m/z 150)

N/A 150 [MH – H2O]+

150 (9%)

135 (18%) TBD TBD TBD

121 (36%)

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119 (100%)

109 (72%)

91 (64%)

Pseudoephedrine 165.23 166 [M + H]+

148 (100%) 172.0 0.205 14.5

Secobarbitol 238.28 237 [M – H]-

194 (100%) 172.5 0.296 20.0

Styphnic acid 245.11 244 [M – H]-

227 (100%) N/A N/A N/A

Δ-9-THC 314.47 315 [M + H]+

259 (79%)

172.0 0.360 17.0

221 (29%)

207 (21%)

193 (100%)

181 (26%)

135 (38%)

Turpentine†

(Pinene) 136.24

137 [M + H]+137 (10%)

N/A N/A N/A 155 [MH + 

H2O]+ 95 (35%)

81 (100%)

Triazolam 343.23 344 [M + H]+

315 (26%)

172.5 0.390 14.5

308 (100%)

Trinitrotoluene

(TNT)‡ 227.13

227 [M – H]-

TBD TBD TBD TBD

226 [M]-.

210 [M – OH]-

197 [M – NO]-

Zaleplon 305.45 306 [M + H]+

288 (18%)

264 (100%) 173.5 0.390 23.0

236 (34%)

Zolpidem 307.4 308 [M + H]+

263 (100%)

173.0 0.370 15.5

235 (56%)

Zopicolone 388.81 389 [M + H]+

345 (100%)

173.0 0.545 15.0

277 (70%)

245 (52%)

217 (35%)

†Headspace of this analyte was analyzed via APCI N/A = MS/MS confirmation not possible due to low mass cutoff 

‡ Analyzed via LTP only TBD = exact assignments still in progress 

* Tentative Assignment = Analyzed in Negative-Ion Mode

** Relative intensities of observed transitions included (0-100%)

3.1.3 Comparison of Spray and Ambient Ionization Methods 

Spectra collected utilizing spray-based conventional (ESI) and ambient (DESI, PSI) 

ionization techniques on target analytes are marked by high intensity signatures for the 

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protonated molecule, similar to data generated on lab-scale instrumentation. These techniques 

are typically “soft” ionization methods, meaning little to no fragmentation is seen during initial 

ionization, but some of these analytes do show in-source fragmentation. This unintentional 

fragmentation stems from the ion optics used for ion transport from ambient conditions (i.e.

capillary inlet and subsequent ion focusing electrodes) into the reduced-pressure vacuum system, 

and they can be partially controlled by manipulating the potentials applied to said optics. The insource fragments seen are reproducible and coincide directly to common MS/MS transitions for 

each specific analyte, allowing them to be used for enhanced analyte confirmation. 

To assess the efficacy of the implementable ionization methods, comparison studies 

between ESI, DESI and PSI-MS were undertaken, using methamphetamine as a model system. 

Characteristic spectral data can be seen in Figure 3-6.

Figure 3-6. (a) ESI, (b) PSI, and (c) DESI mass spectra collected on the Flir AI-MS for 15 ng of 

methamphetamine. As seen, the obtained spectra are quite similar. ESI data was collected on a 1.5 ppm 

methamphetamine solution flowed at 5 μL/min for 2 min, resulting in a total analyzed mass of 15 ng. 

 As seen in Figure 3-6, spectra collected from the differing ionization methods are marked 

by high similarity in regards to ions seen; however, when the overall signal intensities are 

compared amongst the data, there are some distinct differences. ESI data seen in Figure 3-6a is 

marked by high intensity and very low baseline noise, typical of overall ESI-MS data collected 

on the Flir AI-MS 1.2. When a similar total amount of methamphetamine (15 ng) is spotted as a 

residue onto a paper substrate, the signal intensity generated from direct PSI analysis is nearly 

identical to ESI, except for a slightly higher degree of in-source fragmentation that increases the 

yield of corresponding m/z 119 and m/z 91 fragments and other chemical noise resulting from 

the substrate itself. The performance of PSI in these studies shows its analytical potential, 

warranting further investigation. 

When analyzing a 15 ng residue of methamphetamine deposited onto porous Teflon, 

DESI produces the lowest signal intensity at nearly 1500 arb. units. As DESI is a two-stage 

ionization method (that is, the DESI spray solvent impacts the surface, projecting secondary 

droplets containing surface-bound analyte towards the MS inlet for detection), it is much more 

0

1000

2000

3000

4000

50 150 250 350 450

Absolute Intensity

m/z

150

119 91

0

1000

2000

3000

4000

50 150 250 350 450

Absolute Intensity

m/z

150

119

91

0

400

800

1200

1600

50 150 250 350 450

Absolute Intensity

m/z

150

119

91

A B

C

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
22

sensitive to sample positioning in respect to the ionization assembly and MS inlet. Of note, 

while the spectral intensity of DESI was less than that of the other tested methods, the 1500 mark 

is still quite high considering the trace sample analyzed; signals of 25 or below are typically 

considered at noise level. Similar performance between these ionization methods is seen with all 

other project analytes investigated. While there are differences in performance between these 

techniques, they are all viable for use on the Flir AI-MS 1.2 system. 

3.1.4 Analysis of Unconventional Surfaces and Complex Samples 

Analysis of residues from flat surfaces like glass or plastic was demonstrated with very 

high throughput and sensitivity, but given the potential complexity of authentic forensic evidence 

in terms of chemical composition, geometry, and size, experimentation on unconventional 

substrates and complex samples was thoroughly investigated. The Flir AI-MS 1.2 performed 

well in this testing, with the suite of ionization method utilized proving robust to a wide selection 

of test samples. Over the course of the project, representative surfaces tested included glasses, 

metals, polymers/plastics, non-stick coatings, common paraphernalia, phone keypads, and many 

others; further detail is provided in Sections 3.2 (Tasks 2) and 3.6 (Task 6). Chemical residues 

residing in latent fingerprints were also shown detectable directly and indirectly through swab 

transfer when utilizing DESI-MS. The ability to rapidly screen and identify chemicals of interest 

from mock samples and authentic forensic evidence was routinely shown, including from soft 

drinks containing adulterants, abused pharmaceutical tablets, “white powder” evidence types (see 

Section 3.6), organic signatures attributed to gunshot residue, and even methamphetamine and 

precursors in real-time during a clandestine synthesis (see Section 3.5).

Representative spectra from our investigation into the effect of cutting agents can been 

found in Figures 3-7 and 3-8. Figure 3.7 shows the direct DESI-MS analysis from a residue 

containing the synthetic cathinone MDPV (80 ng) in the presence of two common cutting agents, 

phenacetin (analgesic, 136 ng) and benzocaine (anesthetic, 64 ng) placed onto the lip of a used 

prescription pill bottle. The protonated molecules of MDPV, phenacetin, and benzocaine are all 

clearly seen at m/z 276, 180, and 166, respectively, and data is collected instantaneously once the 

pill bottle is placed below the DESI emitter. Figure 3.8 shows the DESI-MS analysis of 100 ng 

of cocaine in the presence of three cutting agents, phenacetin (analgesic, 200 ng), hydroxyzine 

(antihistamine, 200 ng), and benzocaine (anesthetic, 200ng). The protonated molecule of each 

analyte present on the glass slide is easily seen. Identifying cutting agents present simultaneously 

with the illicit chemical itself in seized drug evidence has the potential to discriminate drug 

manufacturers and suppliers 

Latent fingerprint analysis via DESI-MS has been shown to not only allow suspect 

identification like traditional developer-based methods, but also provide insight regarding 

substances that the individual has come in contact with through other chemical signatures present 

in collected spectra. To show the ability to screen chemical residues from latent fingerprints 

with DESI on the Flir AI-MS 1.2, a fingerprint was deposited onto a glass slide after exposure to 

1 μg of MPDV spiked via a solvent aliquot. After complete evaporation of the solvent, a latent 

fingerprint was transferred onto a glass microscope slide. Without further preparation, the 

fingerprint was directly screened via DESI-MS, yielding the spectrum seen in Figure 3-9. The 

protonated molecule of MDPV is clearly present. Interestingly, protonated nicotine is also seen 

at m/z 163, present due to fact that the latent fingerprint analyzed was that of a cigarette smoker. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
23

Figure 3-7. Direct DESI-MS analysis of the lip of a 

prescription pill bottle spiked with the synthetic cathinone 

MDPV and common cutting agents benzocaine and 

phenacetin.

Figure 3-8. Positive-ion DESI mass spectrum of 

cocaine in the presence of common cutting agents.

Figure 3-10 shows the PSI-MS mass spectrum obtained from the swabbing of gun 

powder residues deposited onto a glass surface. For this experiment, a small amount of 

Winchester® smokeless powder was deposited, and a paper triangle pre-wetted with a small 

aliquot of acetone (acetone assists in the transfer of powder residue to the paper swab and 

dissolvation) was used to swab the surface. Immediately, the paper swab was placed into the 

high voltage mount (as seen in Figure 3-4), and a 1 μL aliquot of spray solvent (4:1 

methanol:water with 0.1% formic acid) was added to produce ionization. After roughly 2 sec. of 

delay (as the analyte must migrate through the paper to the triangle point), characteristic spectra 

of the smokeless powder is collected, yielding ion signatures for the organic constituents nnitrosodiphenylamine (m/z 199), diphenylamine (m/z 170), and ethyl centralite (m/z 149, seen as 

an in-source fragment). In total, this experiment took less than 1 minute to perform. Utilizing 

PSI-MS to investigate trace residues attributed to gunshot residue (GSR) is an interesting future 

application of this portable MS system. 

Figure 3-9. Direct DESI analysis of a latent fingerprint 

deposited onto a glass slide. Before deposition, the pad 

of the finger was spiked with MPDV (seen at m/z 276). 

A signature for nicotine is also seen due to the test 

subject handling a cigarette prior to this experiment.

Figure 3-10. PSI mass spectrum collected on the Flir AIMS 1.2 from the direct swabbing of Winchester® 

smokeless powder from a solid surface. 

0

20

40

60

80

100

50 150 250 350 450

[Benzocaine + H]+

[Phenacetin + H]+

[MDPV + H]+

166

180

276

Relative Abundance

m/z

0

50

100

50 150 250 350 450 Relative Abundance

m/z

304

375

180

166

138

Hydroxyzine

Cocaine

Phenacetin

Benzocaine

0

20

40

60

80

100

50 150 250 350 450

276

[MDPV + H]+

163

[Nicotine + H]+

Relative Abundance

m/z

0

50

100

150

200

250

300

350

100 150 200 250 300 350 400 450

Ion Intensity

m/z

149

In-source Fragment of Ethyl Centralite

170 [Diphenylamine + H]+

199 [N-nitrosodiphenylamine + H]+

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
24

3.1.5 Negative-Ion Mode on the Flir AI-MS 1.2 

 While a majority of analytes of forensic 

interest shown applicable to the Flir AI-MS 1.2 

are optimally detected in positive-ion mode, 

negative-ion mode capability of the system can 

be utilized to extend viability towards analytes 

that exclusively or primarily deprotonate during 

ionization (i.e. barbiturates). To demonstrate 

negative-ion mode detection of compounds of 

interest, select barbiturates of high probability of 

abuse, including amobarbitol, pentobarbital, 

phenobarbital, and secobarbitol, were 

successfully investigated. Figure 3-11 shows 

representative spectra for (A) ESI-MS and (B) 

ESI-MS/MS analysis for secobarbitol. Overall 

simplicity of collected spectra in both modes is comparable, while overall signal intensity during 

negative-ion mode operation was lower compared to that of positive-ion mode. Increasing the 

ionization time (i.e. the time period that externally-generated ions are allowed to fill the CIT 

mass analyzer prior to generation of a mass spectrum) from the typical 150 ms to 450 ms signal 

was able to rectify some of this signal loss in negative-ion mode operation. 

3.1.6 Explosives Analysis and Implementation of LTP-MS

To test application to common military explosives and ordnance-related species, surfacebound residues were investigate at low levels (100 ng) with the on-board DESI ionization source 

of the Flir AI-MS 1.2. The most sensitive way to detect common military explosives (RDX, 

HMX and PETN) via DESI-MS is through doping the spray solvent with the Cl- anion 

(commonly from small volumes of HCl or NaCl), which creates chloride-bound adducts with the 

analytes. Interestingly, these chloride-bound adducts are not observed in DESI-MS testing of 

explosives on the AI-MS 1.2 at any appreciable level, as well as signatures for another common 

explosive, TNT. As DESI-MS analysis of explosives using the chloride adduction methodology 

is quite routine on larger-scale mass spectrometers, as was validated in experiments not reported 

here, this result was not expected. This phenomenon potentially arises from the optics utilized 

for ion introduction at the high pressure stages of the system energizing the formed adducts and 

making them unstable; this also can cause the in-source fragmentation observed for other 

analytes on the Flir AI-MS 1.2.

 Interestingly, DESI-MS was shown applicable to low-level explosives related to primer 

and detonator mixtures and commonly found in the “volatile bouquet,” chemicals detected in the 

headspace surrounding armaments. Negative-mode DESI-MS spectra were obtained from 

surface residues of 100 ng for the following analytes: styphnic acid (i.e. trinitroresorcinol, 

explosive used to produce lead styphnate, detected at m/z 244 [M – H]-

), 1,3-dinitrobenzene

(volatile explosive, detected at m/z 168 [M]-.), and 2,4-dinitrotoluene (volatile explosive, 

detected as m/z 181 [M – H]-). Positive-mode DESI-MS was also used to investigate ethyl 

centralite, an organic constituent found in gunshot residue (GSR). 

Figure 3-11. (A) ESI-MS and (B) MS/MS spectra

collected for secobarbitol using the Flir AI-MS 1.2 in 

negative-ion mode. Deprotonated (i.e. [M-H]-) 

secobarbitol can be seen at m/z 237, with its 

characteristic MS/MS fragment signature at m/z 194.

0

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300

450

600

750

100 200 300 400

Absolute Intensity

m/z

237

0

40

80

120

160

100 150 200 250

194

A B 237

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
25

 To accommodate the nonperformance of direct detection of military-grade explosives via 

DESI-MS, a custom-built, LTP ionization source was constructed and tested (as depicted in 

Figure 3-3). Initial characterization of the source was performed using TNT as a model 

explosive analyte. Representative negative-mode LTP-MS spectra were readily obtained for 100 

ng surface residues of TNT, as seen in Figure 3-11. Several ion signatures are seen for this 

analyte on the Flir AI-MS 1.2, including the 

molecular (m/z 227) and deprotonated (m/z 

226) ion and simple losses of OH (m/z 210) 

and NO (m/z 197), all of which have been 

reported in literature using lab-scale mass 

spectrometers.35

These initial results allude to LTP-MS 

being an effective ionization method when 

considering explosives analysis on this 

portable system, and it warrants further 

investigation. Due to the overall success of the 

ESI/DESI assembly on the Flir AI-MS 1.2, 

DESI-MS was chosen as the primary ionization 

source of emphasis to this project. 

3.1.7 Analytical Characterization 

Spectral Data Quality and Accuracy 

Mass spectral data collected using both conventional and ambient ionization methods on 

the Flir Systems AI-MS 1.2 are congruent with that obtained on lab-scale MS instrumentation, 

and important attribute in the pursuit of adopting this technology as an accepted method for 

crime scene investigation and forensic analyses. 

Spectral quality (in terms of accuracy of m/z determinations and relative abundance in 

both MS and MS/MS mode) was tested by direct comparison with a commercially-available, 

spectral reference database. Through collaboration with Dr. Herbert Oberacher (Associate 

Professor, Innsbruck Medical University, Austria), creator of the Wiley Registry® of Tandem 

Mass Spectral Data (MSforID), data obtained on the Flir AI-MS 1.2 was compared to that of an 

array of other MS instrumentation and analyzer classes. The MSforID database contains spectral 

data obtained on commercial, lab-scale QqTOF instrumentation, but does not presently contain 

any MS data generated on portable MS prototypes, making this a pioneering study. To compare 

to the database, MS and MS/MS data (processed as m/z assignment and relative intensity) using 

spray and ambient ionization techniques (ESI, DESI, and PSI) for thirty-two total “blind” 

analytes, including five negative controls (i.e. compounds not currently present in the MSforID 

database), were compared to the library, providing the correct identification for all positive 

controls tested with high sensitivity (i.e. true positive rate). Authentic seized evidence ranging 

from bulk powder to trace residue was also able to be rapidly identified, providing accurate 

determinations and demonstrating high potential for use in forensic casework and potential crime 

scene investigation. Library searching through the Wiley Registry was shown to provide both 

rapid and highly accurate chemical identification without the need for spectral interpretation by 

the end-user, allowing operation by non-technical personnel. 

Figure 3-11. Negative-mode LTP-MS mass 

spectra of 100 ng TNT deposited onto a glass 

surface. Upon analysis with the plasma probe, 

several ion signatures corresponding to TNT are 

seen, adding to the selectivity of the analysis.

0

20

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100

50 100 150 200 250 300 350 400

Relative Abundance

m/z

[TNT - NO]-

[TNT - OH]-

197

226

210

227 [TNT] -

[TNT - H]-

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
26

For this study, correlation between collected data and the reference spectra is calculated 

as a “probability of match” known as the RAMP variable, ranging from 1-100. This variable 

does not read as a percentage per-se (where 60 means 60% match); any collected value over 40 

is considered a positive match with this database. Figure 3-12 shows the comparison of an ESIMS/MS “sample” mass spectrum collected on the Flir AI-MS 1.2 from authentic 

methamphetamine evidence and the ESI-MS/MS “reference” mass spectrum present in the 

MSforID database. 

In-source fragmentation observed on the AIMS 1.2 was shown to complicate library searching 

for certain analytes. Phenylephrine (Figure 3-13a) 

was of particular interest, as it possesses an in-source 

fragment at m/z 150 that when isolated and 

fragmented, results in fairly similar MS/MS data to 

that of methamphetamine; methamphetamine is seen 

in ESI/DESI/PSI spectra as m/z 150, also, 

exacerbating the issue. This occurrence of similar 

data is a potential issue for instrument users, as it not 

only results in a subsequent misidentification when 

compared to the MSforID database, but poses a 

problem for field implementation. The incorrect 

usage of phenylephrine as a precursor in clandestine 

methamphetamine production is becoming more 

prevalent as difficulty in ephedrine/pseudoephedrine 

acquisition increases. 

The misleading identification of the m/z 150 

in-source fragment of phenylephrine as 

methamphetamine can be explained by the 

functional principle of the MSforID search 

algorithm. In essence, this algorithm was optimized 

to give preference to compounds with matching 

precursor ions (that is, the ion that is isolated for MS/MS analysis). Therefore, when the insource fragment of phenylephrine is compared to the molecular ion of methamphetamine library 

entry, the algorithm detects the nominal precursor and fragment ion m/z assignments as identical, 

resulting in a misidentification. This phenomenon is represented in ESI-MS and MS/MS mass 

spectra collected on the FLIR AI-MS 1.2 for phenylephrine and methamphetamine in Figure 

3.13. As the fragmentation pattern of phenylephrine does contain ions specific only to this 

analyte, further refinement of the library identification algorithm to include these signatures 

could negate false identification of phenylephrine as methamphetamine.

Limit of Detection and Quantitative Ability 

 Conventional and ambient ionization methods coupled to the Flir AI-MS 1.2 performed 

quite well in regards trace analysis of target analytes. Sensitivity towards illicit chemical 

detection has surpassed expectations so far regarding residue analysis, yielding limits of 

detection (LOD) in the low-to-sub nanogram (ng) range; in fact, a LOD of 500 picograms was 

recorded for residues of ecstasy (MDMA) via DESI-MS. All of the solid-phase analytes listed in 

Table 3-1 have been detected at 100 ng, and in most cases, at much lower amounts. The 

Figure 3-12. Comparison of the ESIMS/MS “sample” spectrum of authentic 

methamphetamine evidence collected on the 

Flir AI-MS 1.2 to the ESI-MS/MS reference 

spectrum present in the MSforID database. 

A corresponding RAMP value of 75 was 

obtained by comparing the characteristic 

MS/MS fragments present at m/z 119 and 

m/z 91. 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
27

instrument also shows high sensitivity towards DESI-MS analysis of swabs utilized to probe 

surface-bound residues. Table 3-2 shows representative detection limits for surface-bound 

residues deposited on surface of interest in clandestine settings. Here, residues of 

methamphetamine and its pseudoephedrine precursor were sampled via a wetted transfer swab, 

and the swab was then analyzed directly via DESI-MS. As seen, sub-μg detection limits were 

obtained, which is notable considering the variables involved in swab transfer and imperfections 

of the swab surface towards DESI analysis. 

Figure 3-13. ESI-MS and MS/MS mass spectra collected for phenylephrine and methamphetamine. (A) 

ESI-MS spectrum of phenylephrine, with the protonated molecule present at m/z 168, as well as an insource fragment (loss of water) at m/z 150. (B) ESI-MS/MS of protonated phenylephrine, yielding m/z 

150 through dehydration. (C) ESI-MS/MS of the m/z 150 in-source fragment. Several products are 

present, with m/z 119 and m/z 91 being similar to MS/MS analysis of methamphetamine. (D) ESI-MS of 

methamphetamine, showing the protonated molecule at m/z 150 and characteristic in-source fragments at 

m/z 119 and 91. (E) ESI-MS/MS of protonated methamphetamine. 

Table 3-2. Detection limits for methamphetamine and pseudoephedrine residues swabbed from 

surfaces of interest

Substrate Methamphetamine Pseudoephedrine

Pill bottle 350 ng 500 ng

Steel 325 ng 300 ng

Enamel 225 ng 475 ng

Nonstick 200 ng 450 ng

Glass 400 ng 500 ng

0

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100

50 150 250 350 450

Relative Intensity

m/z

168

150

0

50

100

100 150 200 250

168

150

A B 168

0

20

40

60

80

100

50 150 250 350 450

Relative Intensity

m/z

150

119

91

0

50

100

50 100 150 200

150

119

91

D E 150

0

50

100

50 100 150 200

Relative Intensity

m/z

150

135

109 119

91

C 150

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
28

Detection limits obtained in MS/MS mode were shown to be highly sensitive to the 

instrumental settings that control precursor ion isolation and fragmentation via collision-induced 

dissociation. As part of our efforts of develop optimized methods for operation and 

comprehensive spectral reference libraries, MS/MS settings were meticulously optimized to 

produce favorable levels of fragment ion intensity and diversity (for chemical identification 

purposes); further detail regarding these efforts can be seen in Section 3.4. To demonstrate this 

effect, detection limits for the emerging illicit chemical desomorphine and its precursor codeine 

from representative surfaces were assessed via swab transfer DESI-MS/MS using both nonoptimized, factory-default settings and our own optimized variables. The use of desomorphine 

(street name "krokodil”) has been seen in Europe, but recent reports of its production and use in 

the U.S. have made it news-worthy As seen in Table 3-2, detection limits obtained using 

optimized MS/MS settings (mid to low ng) were more than an order of magnitude lower than 

those using default settings (low μg). 

Table 3-2. DESI detection limits utilizing optimized and non-optimized (default) 

MS/MS conditions 

Default Optimized

Surface Desomorphine Codeine Desomorphine Codeine

Steel 3 μg 5 μg 90 ng 100 ng

Nonstick cookware 2.5 μg 2 μg 100 ng 150 ng

Enamel cookware 1 μg 4.5 μg 200 ng 200 ng

PET bottle 1.5 μg 3 μg 100 ng 270 ng

Glass 1 μg 5 μg 150 ng 350 ng

 While the Flir AI-MS 1.2 has been extensively demonstrated as a rapid, yet sensitive 

screening method, the ability to quantitatively assess samples and surfaces of interest could be of 

interest to forensic investigations. To test this capability, calibration curves were generated for 

surface-bound samples of ketamine, MDMA, and heroin using DESI-MS, as seen in Figure 3-14. 

Modest linearity was obtained for these studies, with R2 = 0.9976 (heroin) representing the best 

calibration data obtained. To construct these curves, standard solutions of each analyte were 

spotted onto glass substrates to reach the target deposited mass. The average of four replicates 

for each deposited mass was used for plotting purposes. Linear dynamic range varied from 1.5 

(heroin) to 2.25 (MDMA) orders of magnitude. 

 Precision of each data point obtained is represented by the included error bars, which are 

relatively large in some instances. This loss of reproducibility (and therefore linearity) comes 

from the numerous variables that must be controlled during DESI-MS analysis, including surface 

preparation, orientation of the sample surface relative to the DESI analysis point, and positioning 

relative to the inlet capillary of the Flir AI-MS 1.2 (this variable is particularly crucial given the 

reduced vacuum system of the instrument). While reproducibility of routine analysis does 

increase with user experience, it is anticipated that semi-quantitative analysis on the Flir AI-MS

1.2 represents the best-case scenario when utilizing DESI-MS, and even then may be difficult 

when additional surface variables are introduced (e.g. porosity, dirty surfaces, fingerprint oils, 

etc.). While viable quantitative data could be generated using the conventional ESI ionization 

source, requiring generation of sample solutions from forensic evidence, it is our opinion that 

ambient MS performed with the Flir AI-MS 1.2 is best suited for rapid screening purposes, 

where it has been demonstrated as highly proficient for common forensic analytes. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
29

Figure 3-14. Representative calibration curves generated 

via DESI-MS from surface residues of known mass, 

depicting linearity for (A) ketamine, (B) MDMA, and (C) 

heroin. Modest linearity is obtained over at least two orders 

of magnitude of deposited mass. The average of four 

replicates for each mass was used for plotting purposes.

Sample Throughput 

A major benefit of direct sample analysis via ambient MS is enhanced throughput over 

other techniques requiring extensive sample preparation. To assess sample throughput on the 

Flir AI-MS 1.2 with DESI-MS, trace residues (100 ng) of the synthetic cathinones MDMA (3,4-

methylenedioxy-methamphetamine), MDPV (3,4-methylenedioxypyrovalerone HCl), methylone 

(3,4-methylenedioxy-N-methylcathinone HCl), and mephedrone (4-methylmethcathinone HCl) 

were spotted separately onto a printed teflon slide and analyzed in sequence by rastering the 

substrate by hand at a rate of ~1 mm/sec, as seen in the selected ion chromatograms depicted in 

A

B

C

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
30

Figure 3-15. The entire analysis of all four samples took ~35 sec, including several seconds of 

blank data collection for background subtraction. The protonated molecule for each analyte is 

seen in high abundance at the expected time intervals (i.e. the timepoint to when that spot 

underwent desorption/ionization), and no carryover was recorded, as evidenced by each selected 

ion chromatogram retreating back to noise level once the corresponding sample spot is no longer 

in the ionization region. The rapidity of sample screening and resistance to chemical carryover 

seen on the AI-MS 1.2 would be of great benefit if utilized for authentic evidence screening. 

Figure 3-15. Selected, color-coded ion chromatograms for 4 synthetic 

cathinones spotted in sequence onto a glass slide. By rastering by hand 

underneath the DESI source assembly, signatures of each analyte are 

seen at the corresponding time of analysis. No carryover is seen 

between analytes

Reliability (False Positive/False Negative Rates) 

As seen by Table 3-1, numerous analytes of forensic relevance have been successfully 

detected and characterized using the Flir AI-MS 1.2, but for true application at crime scenes or 

other sites of interest, reliability of data obtained and accurate analyte identification is just as 

crucial as broad applicability. To test false positive/false negative rates on the Flir AI-MS 1.2 

using DESI-MS, two separate studies were completed. 

First, 100 ng residues of cocaine on glass surfaces were used as a model sample for direct 

surface screening via DESI. Here, a total of 200 samples were analyzed (100 “positive” samples 

where cocaine residue was present and 100 “negative” blank slides with no cocaine residue) over 

a time period of several weeks. Acquiring instrumental data at differing date and time helps to 

show inter- and intraday variability of results. All samples (positive and negative samples) were 

analyzed, and the generated data were simultaneously compared to predetermined library entries 

for cocaine DESI-MS (protonated cocaine at m/z 304) and DESI-MS/MS (fragmentation of the 

m/z 304 precursor to produce the characteristic m/z 182 fragment ion) data. Specifics of this 

library searching protocol are described in detail in Section 3.4. For this comprehensive false 

positive/false negative rate study, a positive “confirmation” was denoted by the library protocol 

both warning the presence of cocaine in MS mode and alarming the confirmation of cocaine via 

MS/MS. A negative response was denoted by a lack of both the warning and alarming of 

cocaine. For the 200 sample set, the Flir AI-MS 1.2 performed perfectly, that is it recorded a 0% 

false positive and 0% false negative rate, successfully identifying all true cocaine residues and 

0

1000

2000

3000

4000

0 5 10 15 20 25 30 35 40

Signal Inensity (AU)

Time (sec)

MDMA

MDPV

Methylone

Mephedrone

Background

Collected

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31

blank samples correctly analyzed. To visually examine inter- and intraday spectral variability for 

these repetitive analyses, the MS (Figure 3-16) and MS/MS (Figure 3-17) intensities were plotted 

with time dependence for all 100 “positive” cocaine samples. The average of the MS mode 

intensity seen was 3058 ± 2648 AU, showing that there was a decent amount of variability in 

spectral intensity day-to-day, further suggesting that this platform is better suited for screening 

and identification of forensic evidence, not quantitative assessment. A similar amount of 

variability is seen in the corresponding plot of the MS/MS results. 

Figure 3-16. Graphical depiction of spectral intensity 

obtained for all 100 “positive” confirmations of cocaine 

in MS mode for direct DESI-MS surface analysis. The 

intensity of the protonated molecule at m/z 304 is 

tracked over date and time of analysis. Statistical 

analysis of the dataset is seen in the corner inset.

Figure 3-17. Graphical depiction of spectral intensity 

obtained for all 100 “positive” confirmations of cocaine 

in MS/MS mode for direct DESI-MS surface analysis. 

The intensity of the corresponding fragment ion at m/z 

182 for the isolated m/z 304 precursor is tracked over 

date and time of analysis. 

In a second study, the variability of utilizing surface swabbing for probing surface 

residues was investigated. Here, 200 total control samples (100 “positive” glass slides 

containing 100 ng residues of cocaine and 100 blank “negatives”) were analyzed by using a prewetted swab to interrogate the glass slide, introducing said swab without further preparation into 

the DESI source of the Flir AI-MS 1.2. As in the first study, an automated library searching 

protocol (See Section 3.4) was used to confirm the detection and identification of cocaine from 

each sample. Samples were analyzed over a one month period at differing times for variability 

testing. This study yielded a total of zero false positives and four false negatives. Signal intensity 

varied greatly for both MS screening and MS/MS verification, more so than direct analysis of 

glass slide via DESI-MS, Overall MS/MS intensity tended to be lower, as the cocaine residue 

was partially exhausted during base MS scanning. The enhanced deviation of this study is a 

result of inherent variability of the surface swabbing and swab placement in the DESI source. It 

is anticipated that the extent and location of cocaine transfer to the swab can change. This source 

of variability, in addition to the sensitivity to positioning inherent to swab analysis, suggests the 

use of physical transfer swabs is limited to qualitative screening purposes. 

 Taking into account both reliability studies, the Flir AI-MS had a 100% success rate 

for positive controls and 98% success rate for negative controls for 400 control samples.

3.2 Task 2: Investigate Alternative Surface Sampling Methodologies 

For traditional DESI-MS, the actual analysis point (i.e. the area on the surface of interest 

that is undergoing desorption/ionization) is relatively small (~1 cm2) and is directly in front of 

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12000

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16000

18000

10/26 10/28 10/30 11/1 11/3 11/5 11/7 11/9 11/11 11/13 11/15 11/17 11/19 11/21 11/23

Peak Height (m/z 304, AU)

Date and Time of Experiment (MM/DD, 2012)

MS of Cocaine (m/z 304) Ave. = 3058 2648 Min. = 707 Max. = 16390

±

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10/26 10/28 10/30 11/1 11/3 11/5 11/7 11/9 11/11 11/13 11/15 11/17 11/19 11/21 11/23

Peak Height (m/z 182, AU)

Date and Time of Experiment (MM/DD, 2012)

MS/MS of Cocaine (m/z 182) Ave. = 3957 2922 Min. = 362 Max. = 14673

±

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
32

the electrospray emitter of the ionization source (see Figures 3-2A and B). While this is suitable 

for small substrates of simple geometry, large surfaces pose significant problems for DESI-MS. 

For larger surface areas or samples with complex geometry, physical transfer of chemical 

residues via surface swabbing is an effective method that can be rapidly applied to DESI-MS 

analysis on the Flir AI-MS 1.2. It is expected that many substrates too large in size to allow 

positioning in the ionization source can be screened by using a swabbing protocol followed by 

direct analysis of said swab material. 

To determine the viability of swab transfer 

coupled to DESI-MS, known amounts of analyte were 

deposited onto surfaces by spotting aliquots of standard 

solutions and allowing complete evaporation of solvent. 

Several swab candidates were identified and tested to 

determine the best candidate for adoption, with attributes 

including transfer efficiency, chemical noise during MS 

analysis inherent to the swab, ease of positioning in the 

DESI assembly, and reliability of analysis. Tested swabs 

included chromatography paper (Whatman 1 Chr, GE 

Healthcare Life Sciences), knitted polyester (LTP70R, 

Berkshire Corporation), non-woven hydroentangled foam 

polyester (LTN70F, Berkshire), polyurethane foam 

(LTO70R, Berkshire), and spun cotton “Q-Tip”-style 

applicator (A5005-1, American Scientific Products), as 

shown left to right in Figure 3-18. Note that Whatman chromatography paper that can be 

utilized for PSI-MS was also included, as the paper substrate itself can be implemented as a 

physical transfer swab prior to PSI analysis. Extensive testing of wet vs. dry swabbing shows 

that dampening the swab prior to surface probing (typically with 5-10 μL of methanol or other 

suitable solvent) results in significantly higher transfer efficiencies and subsequent analyte 

intensity. 

To show the potential of direct transfer swab analysis, mock scenarios of forensic interest 

were created and tested. For instance, using wetted transfer swabs to probe latent fingerprints for 

chemical residues from surfaces not amenable to direct DESI analysis was demonstrated. Figure 

3-19 depicts using a physical transfer swab to probe latent fingerprints from a cellular phone. To 

confirm this capability, 500 ng of methylone was deposited onto the glass display of a 

touchscreen cellular phone. A dampened, sterile swab was then quickly run over the entire glass 

surface and directly analyzed, with resultant data seen in Figure 3-20. The protonated molecule 

of methylone is seen at m/z 208 even when present at trace levels. Swabbing of latent 

fingerprints on large surfaces found at a crime scene (e.g. drywall, windows, and countertops) 

could be done in a similar fashion, keeping in mind that said method would be destructive to the 

fingerprint topology. It is expected that a similar swabbing protocol could be used extensively in 

clandestine methamphetamine operations, where residue analysis from unmarked glassware and 

other paraphernalia could be high utility, and this expounded on in Section 3.5 of this report. 

Figure 3-18. Examined commercial 

swabs. From left to right: Whatman 

chromatography paper used for PSI-MS, 

woven fiber, non-woven foam, 

polyurethane foam buccal, and spun cotton

“Q-Tip”-style. Also seen is a residuecontaining glass slide used for physical 

transfer studies.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
33

Figure 3-19. Depiction of using a 

transfer swab to probe the keyboard 

of a cellular phone for residues 

found in latent fingerprints.

Figure 3-20. DESI mass spectrum of a 

swab after probing the touchscreen display 

of a cellular phone. The protonated 

molecule of methylone (spiked onto phone 

prior to swabbing) is seen at m/z 208.

3.2.1 Wet vs. Dry Swabbing and Transfer Efficiencies 

Characterization of surface probing with “wet” swabs vs. dry swabs was undertaken; 

swab “wetting” comes from the predisposition of solvent directly to the swab head. It was 

anticipated that wet swabbing would take advantage of surface-bound analyte solubility, 

removing more residue from the sample surface and increasing the sensitivity of the overall 

method. Initial test involved the use of methanol, a common organic solvent with high solubility 

towards drugs of abuse, and wet swabbing drastically outperformed dry swabbing. It is 

important, though, not to overly wet the utilized swab, as excess solvent can dissolve the surface 

residue, wick from the swab during contact, pool, and dry, reducing the transfer efficiency of the 

desired experiment. Damp, not saturated, swabs are recommended. To this end, each particular 

swab was determined to have an optimal wetting volume. The success of this study warrants 

further investigation, particularly with solvents of low human toxicity (i.e. isopropanol, water) 

for instances where direct skin swabbing is of interest. Skin swabbing could provide interesting 

opportunities in search and seizure and post-mortem/toxicology applications. 

The transfer swabbing/DESI-MS protocol has two distinct phases that need characterized 

in order to obtain full method optimization: assessment of swab transfer efficiency and ionization 

efficiency of direct DESI analysis from used swabs. Using standard GC/MS procedures, transfer 

efficiencies (i.e. how much analyte can be transferred from surface to the swab) for commonlyavailable swabs seen in Figure 3-18 were determined for methamphetamine residues deposited 

onto glass. Utilized swabs were solvent extracted in methanol, and internal standard (d3-

methamphetamine) doped extracts were analyzed via GC/MS and compared to calibration data to 

determine concentration; transfer efficiencies were then be back calculated after incorporating 

volume and the pre-determined extraction efficiency (i.e. how much analyte can be extracted 

from the used swab) for each swab type. 

Experimentally-determined extraction and transfer efficiency values were found for all 

swab types and reported in Tables 3-3 and 3-4, respectively. As seen, swab composition not 

only effects the relative efficiencies investigated, but also the repeatability of the surface transfer 

process, which is not surprising given the inherent variability of this swabbing action. 

Interestingly, the PSI paper substrate has very high transfer efficiency for residues below 2 μg, 

which could be another benefit of investigating this ambient ionization method for physical 

transfer experimentation. The buccal swab, in contrast, has been shown to recover only around 

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100

50 150 250 350 450

208

[Methylone + H]+

Relative Abundance

m/z

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and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
34

58%, but can do so for up to ~16 μg of the target compound. Thusly, usability factors must be 

taken into account when validating the various swabs and making our final recommendation for 

swabbing procedures. 

Table 3-3. Extraction Efficiencies for Physical Transfer Swabs 

Extraction Efficiency For Cocaine Residues

Type of Swab Average

Polyester Buccal 96.72% ± 6.45%

Woven Fiber 73.28% ± 4.77%

Paper Triangle 

(PSI) 70.92% ± 0.96%

Non-Woven Foam 80.43% ± 1.77%

Spun

Cotton 78.37% ± 3.85%

Table 3-4. Transfer Efficiencies for Physical Transfer Swabs 

Transfer Efficiency For Cocaine Residues

Type of Swab Average

Polyester Buccal 57.49% ± 7.22%

Woven Fiber 67.68% ± 14.99%

Paper Triangle 

(PSI) 98.20% ± 4.05%

Non-Woven Foam 66.78% ± 11.27%

Spun

Cotton 61.90% ± 1.70%

Relative ionization efficiencies of direct DESI analysis from surface swabs (i.e. how 

much analyte can be removed/ionized from the swab surface with DESI) were determined by 

deposition of known quantities of illicit drugs onto swabs of interest and comparison of 

corresponding spectral intensity generated. It was found that ionization efficiency, as expected, 

was effected by the surface composition of each swab. Porous and absorbent materials tended to 

retain the incoming DESI spray and hinder the secondary release of surface-bound analyte 

residue. The paper substrate yielded high ionization efficiency via PSI-MS due the combined 

analyte extraction and ionization process of the technique. Swab geometry also played a role, 

with flat, smaller surface area swabs proving easer to orient in the DESI assembly, enhancing 

ionization efficiency. 

3.2.2 Recommended Transfer Swabbing Protocol 

Considering all factors tested during Task 2, Berkshire polyurethane foam swabs 

(identified as “non-woven foam” in Tables 3-3 and 3-4) were determined to be the best candidate 

for developing optimal transfer swabbing protocols for use with DESI-MS. Prior to use, the 

swab is prewetted with 5 μL of methanol, spread equally by splitting the total volume to both 

sides. Depositing should be closer to the end of the swab head rather than its center. To sample a 

surface of interest, the swab should be held at ~30o relative to the surface with light pressure and 

slowly moved up and down with light pressure across the entire surface with slight rocking to 

expose all of one face of the swab to the surface. Once finished, the other face of the swab was 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
35

utilized to sample the surface in a similar way in the right to left direction to collect as much of 

the potential surface residues as possible. The angle of contact determines the swab area that 

actually contacts the surface of interest. After the surface was sampled, the swab is then 

presented to the DESI spray region using a swab positioning guide from Flir Mass Spectrometry, 

seen in Figure 3-21. The swab is placed within the alignment groove of the guide and initially 

held flush against the right edge of the guide. The swab is then slowly rotated to expose the 

entire swab surface to the DESI spray, and it was then pulled back along the left-right axis by 

approximately 2 mm to expose the swab head region to the spray, again with slow rotation to 

analyze the entire circumference. 

When utilizing the automated library searching protocol developed for the Flir AI-MS 1.2 

(see Section 3.4 for more detail), rotation of the swab should be paused and the swab held in 

place to allow time to collect confirmatory MS/MS scans for that surface region if the software 

interface warns the user of the presence of a potential analyte of 

interest. If the software does not alarm in MS/MS mode within 

~5 seconds, minor adjustments of the positioning along the leftright axis and circumference via rotation should be made. After 

MS/MS investigation ceases by the software, examination of the 

remaining swab surface, as well as the other face of the swab, 

can continue for other potential analytes present. 

After completion of swab analysis and in the event of an 

alarm, a blank swab should be analyzed to ensure no carryover 

from the preceding experiment. If carryover is seen (determined 

by the false alarm for the same analyte detected on the preceding 

analysis), a new swab positioning guide should be placed on the 

ESI/DESI assembly; subsequent blank swab analyses should be 

done to confirm hygiene of the ionization source before the next 

sample is presented. 

3.3 Task 3: Demonstrate Direct Air Analysis Ability via APCI on the Flir Systems 

AI-MS 1.2 

The versatility of the direct capillary inlet on the Flir AI-MS 1.2 allows it to couple to 

most ionization methods that generate analyte ions at ambient conditions. Techniques like DESI 

allow detection of surface-based or solid chemicals, but are typically not applicable to gas-phase 

analytes. High volatility analytes have long been examined using GC/MS, but when 

implementing specialized ionization sources, they can also be analyzed on the Flir AI-MS 1.2 

directly from ambient air. To demonstrate the ability to monitor gas-phase analytes directly from 

the air via APCI, several iterations of source design were undertaken, producing a robust, 

sensitive ionization source easily coupled to the Flir AI-MS 1.2 platform. 

Initial proof-of-principle testing was conducted with a simplified, open air corona 

discharge source (Figure 3-22), allowing continuous screening of near proximity air 

contaminants via APCI. The corona discharge is generated via a high voltage applied to a 

tungsten wire discharge needle. The source itself is quite simple, requiring only 4 kV applied 

under resistivity (10 MΩ) to a thin wire. Spectra generated with this source were congruent to 

that obtained on lab-scale instrumentation, showing high promise of APCI as a fieldFigure 3-21. Photo of DESI swab 

analysis utilizing a swab 

positioning guide from Flir Mass 

Spectrometry.

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
36

implementable technique. On the other hand, safety in regards to inadvertent shock from high 

voltage and ruggedness was a concern, prompting further revision. 

 The second revision featured a polyether 

etherketone (PEEK) enclosure for the corona 

discharge region, while also allowing air samples to 

be pulled through the source via sampling tubing by 

use on a small diaphragm pump (as represented in 

Figure 3-23; this source was similar in design to 

one recently reported in literature on portable MS 

instrumentation.22 The ruggedized source met all 

requirements for completion of project tasks, 

including detection of potential accelerant vapors at 

or below 1 ppm. 

Representative spectra collected using the 

APCI sampling system seen in Figure 3-23 were 

obtained on potential accelerants and chemical 

warfare agent simulants to show field applicability. 

Figure 3-24A shows a positive-mode APCI mass 

spectrum of dimethyl methylphosphonate (DMMP), a common simulant for the agent Sarin, 

showing the protonated molecule at m/z 125 and an in-source fragment at m/z 111 (the hydrated 

phosphonium ion). MS/MS confirmation of the m/z 125 precursor can be seen in Figure 3-24B, 

yielding the characteristic fragments at m/z 93 (phosphonium ion) and m/z 111 (hydrated 

phosphonium ion). Figures 3-24C and D show MS and MS/MS confirmation of turpentine 

vapor, yielding spectra indicative of the natural product pinene. 

Figure 3-23. Schematic of a ruggedized APCI source built for the Flir AI-MS 1.2 and its utilization to 

analyze volatile chemicals of interest (i.e. accelerants, toxic industrial compounds, etc.). An auxiliary 

pump pulls ambient air through a sampling tube of defined length into the discharge region of the APCI 

source. Upon ionization, volatile species are sampled through the inlet system of MS system and 

detected. Unused portions of the air are exhausted (in a safe location, if need be). Utilization of a 

sampling tube allows the instrument and operator to be removed from unsafe areas, yet capable of 

assessing the chemical content of ambient air and samples of interest.

MS Inlet

Corona

Discharge

Flow of 

Volatile Species/Headspace

Samples of Interest

Auxiliary

Pump Exhaust

Figure 3-22. Simplified corona discharge APCI. 

High voltage is applied to a thin wire under 

resistivity. Gas analytes present between the wire 

and MS inlet are ionized and detected.

Wire MS inlet

HV 

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
37

Figure 3-24. Positive-mode APCI mass spectra obtained for volatile headspace of 

(A) the chemical warfare agent simulant, DMMP and (C) turpentine, with 

subsequent MS/MS confirmation provided in (B) and (D), respectively. Simplicity 

of generated spectra depends on the complexity of gaseous headspace analyzed. 

As turpentine is a mixture of several chemicals, obtained spectra are complex, yet 

identifiable.

While functional and demonstrating high performance, the PEEK APCI source body 

possesses potential disadvantages that could complicate its coupling and usage during field 

usage. Briefly, attachment of the source necessitates the removal of the ESI/DESI spray 

assembly due to space constraints caused by its large size. This presents the possibility for 

contamination of the DESI spray body, damage to the emitter tip of the spray head if the source 

is not stored in a secure location, and misalignment of the DESI source once reattached. 

Additionally, the weight of the current APCI source represents a complication during its setup 

due to the possibility of the source placing excess force on the inlet MS capillary. 

In order to minimize these concerns, the final design iteration featured a reduced-size 

APCI source body constructed from lightweight Teflon. As seen in Figure 3-25A, the source is 

small enough to be attached to the inlet capillary while the DESI source body is raised and 

secured in its maintenance position. The design possesses a shielded tungsten discharge needle to 

which the user can quickly attach the voltage lead. The discharge needle is positioned parallel to 

the flow of sample gas and perpendicular to the inlet capillary, as seen in the top view schematic 

in Figure 3-25B. The improved machinability of the polymer-based compression fittings used to 

secure to the MS inlet capillary compared to the stainless steel-based fittings used in the previous 

source enables fine adjustment, optimizing APCI spectral data intensity and minimizing the 

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50 100 150 200 250 300 350 400 450

Relative Abundance

m/z

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125

111

[DMMP + H]+

111

93

125

125

A

B

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Relative Abundance

m/z

81

110

137

95

169

155

151

[Pinene + H]+

0

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50 100 150 200

81

95

137

137

[Pinene + H + H2O]+

C

D

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
38

potential for unwanted arcing between the source and capillary inlet. Overall, this source design 

was determined as the best option for potential field deployment. 

Figure 3-25. (A) Lightweight teflon APCI 

source attached to the Flir AI-MS 1.2 by 

simply lifting the DESI/ESI source in the 

maintenance position and sliding the 

source over the MS inlet capillary. (B) 

Top view schematic showing the 

interworking of the APCI source. The 

discharge needle is parallel to the flow of 

sample gas and perpendicular to the inlet 

capillary.

3.3.1 Assessment of Detection Limits via APCI 

To determine detection limit of APCI analysis on the Flir AI-MS 1.2, defined as a signalto-noise ratio of 3, accurate concentration gas standards were produced and analyzed. Diluted air 

samples containing a known amount of accelerant vapor were flowed directly into APCI source 

and analyzed. Detection limits determined for select chemicals and compilations during these 

studies can be seen below in Table 3-5, along with other volatile chemicals characterized. 

Overall, several analytes have been detected at gas concentrations less than 1 ppm, fulfilling the 

milestone detection limits for the project. Exact detection limits for complex hydrocarbon 

mixtures like gasoline and kerosene were difficult to assess, as calculating the gas-phase 

concentration of each single component depends on its own partial pressure. Detection limits for 

these samples were represented as a dilution factor (volume of sample/total volume of air 

analyzed). 

3.3.2 Analysis of Mock Arson Evidence via APCI-MS

To simulate the direct analysis of evidence that may be present at an actual arson 

investigation, representative charred samples were prepared by ignition with potential 

accelerants. Initial test involved exposing 1 in. x 1 in. x 0.25 in. pinewood blocks with small 

quantities (~5 mL) of a potential liquid accelerant and igniting it in a glass petri dish. The wood 

sample was ignited and allowed to openly burn until all accelerant liquid was exhausted, and the 

block was allowed to become visibly charred before being capped to extinguish any remaining 

HV

Ambient Air (IN) Exhaust (Pumped Out)

(TOP VIEW)

HV Corona Discharge

Airflow

Pumped to

Small Diaphragm

Pump

A

B

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39

flames. Charred samples were then placed in Erlenmeyer flasks sealed with rubber septa for 

transport and to allow generation of headspace vapor within, as seen in Figure 3-26. These 

headspace vapors were then analyzed by APCI after transporting them via the pump-assisted 

sampling tube (shown in Figure 3-23) into the ionization source. 

Table 3-5. Potential Accelerants Investigated with APCI and Associated LODs 

Compound MW (Da) Precursor Ion (m/z) Detection Limit

Acetone 58.08 59 [M + H]+

117 [2M + H]+ 0.5 ppm

Benzene 78.11 79 [M + H]+ Not Tested

Charcoal Lighter Various Various Not Tested

Diesel Fuel Various 101, 136, various 1/100 Dilution

DMMP

(Sarin simulant)

124.08 125 [M + H]+ Not Tested

Ethanol 46.07 93[2M + H]+

139[3M + H]+ Not Tested

Ethyl Ether 74.12 75 [M + H]+

149 [2M + H]+ 0.5 ppm

Isopropanol 60.10 61 [M + H]+

121 [2M + H]+ 2 ppm

Kerosene Various Various Not Tested

Methanol 32.04 65[2M + H]+

97[3M + H]+ 10 ppm

Methyl Ethyl Ketone 72.11 73 [M + H]+

145 [2M + H]+ 0.5 ppm

Methyl Salicylate 

(blister agent 

simulant)

152.15 153 [M + H]+

121 [MH – CH3OH]

+ Not Tested

Trimethyl benzene 120.19

121 [M + H]

+

105 [m/z 121 – CH4]

+

91 [m/z 121 – C2H6]

+

Not Tested

Turpentine

(Pinene)

136.24 137 [M + H]+

155 [MH + H2O]+ 1/100 Dilution

Figure 3-26. Post-burn wood block 

visibly charred and cracked after 

ignition with Coleman Fuel. 

Generated headspace can then be 

analyzed directly via APCI-MS

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and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
40

Charred sample analysis via APCI-MS was shown to produce signatures for residual 

accelerant vapors and combustion and pyrolysis products released from the charred material, but 

also natural products inherent to wood substrates. Representative spectra for pinewood burned in 

the presence of acetone (Figure 3-27A) and Coleman Fuel (Figure 3-27B) show characteristic 

signatures for each particular accelerant, but data is indicates a strong presence of pinenes 

originating from the wood itself. Chemical noise related to the burned substrates themselves 

warrants further investigation to test feasibility of this application of APCI-MS, particularly for 

polymer-based materials like fabrics and carpet commonly found in housing and commercial 

structures; these materials are expected to produce strong hydrocarbon-based combustion 

signatures. 

Figure 3-27. (A) APCI-MS spectrum of headspace vapor collected from pinewood charred in the

presence of acetone, yielding peaks corresponding to the protonated acetone monomer (m/z 59) and 

dimer (m/z 117). Ions attributed to the pine substrate include protonated pinene at m/z 137, along

with m/z 151 and 169. (B) APCI-MS spectrum of headspace vapor collected from pinewood charred 

in the presence of Coleman Fuel, featuring distinct peaks at m/z 113, 127, and 141 originating from 

the accelerant

3.4 Task 4: Develop Comprehensive Mass Spectral Libraries and Optimized 

Methods for Target Chemicals 

Over the course of the project period, high-quality MS and MS/MS spectra and methods 

for their collection were generated for numerous analytes of forensic interest for development of 

a comprehensive mass spectral library; analytes residing in the constructed library can be seen in 

Table 3-1. Optimization of MS/MS instrumental methods was undertaken by systematically 

adjusting ion trap parameters during precursor isolation and fragmentation, as discussed in 

Section 3.4.1. Said MS/MS methods not only gave fragmentation data congruent to our own 

testing on lab-scale MS instruments and that reported by other research groups in literature, but 

also have proven to be reproducible in both inter- and intraday testing; MS/MS comparison 

studies involving the Wiley Registry® of Tandem Mass Spectral Data (MSforID) are described 

further in Section 3.1.7. User software upgrades released by Flir Mass Spectrometry for the AIMS 1.2 allowed creation of semi-automated optimization methods of MS/MS experimental 

conditions and fully-automated library searching protocols based of MS/MS-based data 

dependent scanning, both of which described in detail below. Of note, automated library 

searching has the potential to alleviate the need for spectral interpretation by the instrument 

operator, expanding its use by non-technical operators by incorporating “red light/green light” 

0

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1500

2000

2500

3000

3500

4000

50 150 250 350 450

Intensity

m/z

117 [2Acetone+ H]+

59 [Acetone+ H]+

137 [Pinene + H]+

A

0

500

1000

1500

2000

2500

3000

3500

50 150 250 350 450

Intensity

m/z

127

113

137

141

151

169

B

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been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
41

protocols (i.e. red indications on a graphical user interface affirms the presence of a target 

analyte, green indications that the sample is innocuous). 

3.4.1 Semi-Automated Optimization of MS/MS Method Conditions 

Initial pursuits in optimizing compound-specific MS/MS instrumental methods required 

an intensive, systematic study of all pertinent variables, requiring the user to alter and test all 

combinations of settings for each analyte of interest. Updates to the instrument control software 

(Griffin System Software, GSS) during the project has allowed the streamlining of this method 

development, as fine optimization of compound-specific, MS/MS method conditions can now be 

done in a semi-automated fashion, a process termed “macroing.” The macro function of the new 

version of the software allows the user to automatically scan ranges of critical MS/MS method 

variables, including the frequency of the AC dissociation waveform applied, collision energy 

(i.e. the energy imparted to isolated ions via collision-induced dissociation, CID, with helium 

damping gas), and dissociation time, in order to maximize MS/MS spectral intensity, 

fragmentation efficiency and/or fragment diversity. Purposely introducing a higher diversity in 

generated MS/MS fragments can be beneficial in regards to increasing accuracy of identification 

of isobaric compounds and structural isomers (i.e. codeine and hydrocodone). This macro 

function was used to produce all of the optimized MS/MS parameters reported in Table 3-1.

In order to macro a particular MS/MS condition for a specific compound, ESI-MS was 

primarily utilized due to the need for constancy in spectral intensity. First, fragmentation of the 

compound is examined over a pre-determined range of excitation frequencies, typically between 

170 and 178 kHz using 0.5 kHz increments. By looking at the resulting total ion chromatogram, 

the user can determine the frequency value that results in the highest fragment ion signal 

intensity, as seen in Figure 3-28 for the optimization of MDMA fragmentation. By observing the 

maxima of signal intensity (as denoted with the green arrows) for the primary fragment at m/z 

163 in MS/MS mode, the most effective frequency value can be rapidly obtained compared to 

the slower alternative (i.e. systematic changing of the variable by the user, collection of spectral 

data, and determination of spectral intensity maxima by direct observation). The CID voltage 

variable is then optimized in a similar manner for the compound using the frequency value 

previously determined. Lastly, the optimal values determined for the frequency and voltage are 

used to macro for the dissociation time variable, resulting in idealized values for all three 

variables for generation of MS/MS method files for the specific analyte. Once the main 

variables are optimized, the overall MS/MS method is then used to analyze the same compound 

using other ionization methods (e.g. DESI, PSI) in order to confirm its ruggedness to broad 

usage. As anticipated, utilization of non-optimized MS/MS variables results in substandard 

spectral intensity, as is depicted in Figure 3-29. In the case of MDMA, optimized MS/MS 

variables via macroing produce a 3x higher spectral intensity for the target m/z 163 fragment, 

decreasing the limit of detection for the compound in the process. 

 It should be noted that in the instance of a true unknown analyte observed in an examined 

sample (i.e. compound not found in the developed spectral library), the default MS/MS 

parameters incorporated in the user software should be utilized until rigorously optimized 

settings can be determined on appropriate analytical standards. 

 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
42

Figure 3-28. Total ion chromatogram depicting of macroed frequency variable for MDMA. Numerous 

frequency values can be automatically screened (denoted by the lighter blue trace) to determine the 

value that produces the highest fragment ion signal intensity in the resultant mass spectrum seen in the 

bottom window.

Figure 3-29. ESI-MS/MS of MDMA collected with (A) non-optimized and (B) optimized variables 

collected via macroing. As seen, optimized variables produces 3x higher signal intensity for the target 

fragment of MDMA at m/z 163.

3.4.2 Automated Library Searching via Data Dependent Scanning 

Early success in project-related research has allowed us to expand and broaden certain 

proposed tasks, particularly in terms of developing simplified software intended for nontechnical users. Updates to the control software for the Flir AI-MS 1.2 during the project 

allowed development of automated library searching methods that identify target analytes found 

in investigated samples by comparison to both base MS and MS/MS reference spectra; this, in 

turn, alleviates the need for user interpretation of collected spectra, as well as guides the user 

Highest Signal 

Intensity 

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163 194 163 194

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
43

through the analysis procedure (e.g. documentation, presentation of the sample, saving of 

spectral data, etc.). This operation is referred to “Level 1” methods, herein.

 With Level 1 operation, MS/MS confirmation for target analytes inherent to the presented 

sample has been integrated into the screening method itself rather than requiring the subsequent 

loading and implementation of a standalone MS/MS method specific to each controlled 

substance. The Level 1 protocol is configured to automatically select and run appropriate 

MS/MS confirmation scans as soon as a target generates a warning (i.e. protonated molecule m/z 

collected in base MS mode matches an existing compound in the on-board spectral library) in 

real time, removing the need for operators to manually select the appropriate confirmation 

method. This capability is referred to as data dependent scanning (DDS), as the detection of 

potential MS precursors prompts the automatic loading and running of optimized MS/MS 

settings saved within in the method; these optimized MS/MS conditions were determined via 

macroing, as discussed the previous section. Overall, the user can now screen and identify via 

MS/MS fragmentation up to 28 different analytes found in a single sample, all within a 4 min. 

total analysis time. A detailed description of the Level 1 screening process is provided below, 

with software screenshots for illustrative purposes. 

Operation of the Flir AI-MS 1.2 Using the Level 1 Protocol 

1. The operator is first prompted to load a Level 1 screening method corresponding to the 

type of evidence in question (e.g. Drugs of Abuse, etc.) and enter a sample name for data 

recording and chain of custody purposes. After the instrument performs a quick selfcalibration to ensure proper operation, the user is prompted to introduce their sample 

utilizing their desired ionization method. For the purposes of this description, we will 

focus on our devised Drugs of Abuse method, which performs real-time searches for a 

variety of illicit drugs, abused pharmaceuticals, potential synthetic precursors, and

common cutting agents. 

2. Once the analysis prompt appears, the Level 1 protocol enters Monitor View and begins 

scanning for base MS signatures, particularly parent molecule m/z signatures of analytes 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
44

included in the mass spectral library for the method being used. After the operator 

introduces the sample, (i.e. a physical transfer swab into DESI spray region, as is 

depicted in this description), MS scanning continues for a predetermined amount of time, 

currently set to 4 min. total; of note, if no “warnings” occur within 2 min., the method 

will end to minimize unneeded analysis time. 

3. Real-time spectra obtained during this base MS scanning are compared to a predetermined set of rules for the “warning” thresholds, which include intensity and 

observed duration of protonated molecule signatures matching the spectral database. 

Should an observed spectral peak meet these rules for a certain drug of abuse or other 

illicit substance, the graphical user interface will turn yellow, warning the operator of its 

possible presence; the compound is also identified by name. 

4. After the software registers a “warning,” presence of the suspected controlled substance 

is then verified with compound-specific MS/MS analysis. As stated, the updated 

instrumental software allows confirmatory MS/MS scans to be included in the general 

method itself, no longer requiring separate MS/MS methods to be run by the user for each 

analyte. Any activated MS/MS scans then run sequentially with the base MS scan to 

allow warning of other potential analytes of interest in the sample. The software itself has 

a limit of allowing 28 separate MS/MS scans per Level 1 analysis, which allows 

molecular identification from even the most complicated sample mixtures. 

5. Once initiated, each compound-specific MS/MS analysis will continue for two minutes 

after its starting point and will continue past the two minute cutoff for the MS warning 

scan if necessary. Rules that govern “alarming” with a red-light designation, that is, 

confirmed presence of a compound via MS/MS spectral matching, are contained in 

separate files stored on the AI-MS 1.2 control computer (.MACOI files). “Alarming” for 

the presence of a target analyte via MS/MS spectra will turn the interface red, alarming 

the operator of a confirmed target. The MS/MS scan for that specific analyte will then 

cease, and the software will continue to scan for other target analytes with the time 

remaining. 

In the example shown below, a swab used to collect hydrocodone residue spotted upon a 

glass surface generated yellow “warnings” for both hydrocodone and its isomer codeine, 

as both produce a protonated molecular ion at m/z 300. The software then automatically 

initiates confirmatory MS/MS scans for both hydrocodone and codeine to verify which 

pharmaceutical triggered the alarm, examining differences in the fragmentation spectra 

collected. The codeine MS/MS scan did not detect the presence of its unique fragment 

peak at m/z 215, while the hydrocodone MS/MS scan did detect the presence of its 

unique fragment at m/z 199. As a result, codeine remained at yellow “warning” status, 

while the positive MS/MS result prompted a red “alarm” status for hydrocodone. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
45

Screenshot of the Monitor View during the hydrocodone analysis discussed in Step 5

6. After any Level 1 analysis that warns or alarms for target analytes, advanced users can 

inspect the collected MS and MS/MS spectra by clicking the “Detailed” tab to view the 

raw data; screenshots of this view are seen below. Collected mass spectra are seen in the 

upper left corner, while a list of chemicals that trigged warnings and full alarms is located 

in the upper right with the time at which the trigger was recognized. A chromatogram is 

shown in the lower portion of the screen, depicting specific ion signal over the entire 

experiment. The total ion chromatogram is shown with the green trace, and each 

additional MS/MS scan triggered is given a unique color trace (blue and red). 

Figure 3-30 shows the tentative flow of a typical DESI-MS screening of evidence with the 

Flir AI-MS 1.2 and the developed Level 1 software protocol. The flowchart depicts how the 

method “warns” for potential analytes present and then automatically performs associated 

MS/MS confirmation; when both MS and MS/MS spectra match the on-board spectral library, 

the software “alarms” for a confirmed illicit chemical present. This iterative process continues 

for a pre-set limit (4 min.), after which analysis ends and all warnings/alarms are indicated to the 

user. Confirmed and non-essential evidence can then be documented at the scene and 

transported to off-site labs for further confirmation or storage. After cleaning the ionization 

source to limit cross-contamination, including but not limited to the surface contacting the 

presented sample (see Figure 3-2), the spray head assembly, and MS inlet capillary, a new 

sample can be presented for analysis. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
46

Screenshot of the representative base MS data collected in the Detailed View after 

alarming for hydrocodone

Screenshot of the MS/MS data collected in the Detailed View after alarming for 

hydrocodone analysis

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
47

3.5 Task 5: Demonstrate Detection Capability of Materials of Interest at Clandestine 

Methamphetamine Labs and Investigate Other Forensic Applications 

 Clandestine laboratory installations represent the worst-case scenario for field analysis, as 

the variety of “samples” found are diverse in nature, can be large in quantity, rarely marked and 

stored in proper containers, and most likely located in unsafe conditions. To help provide a 

robust platform for general sample screening in these situations, proof-of-principle 

experimentation on the Flir AI-MS 1.2 focused on synthetic routes for methamphetamine and the 

emerging clandestine drug desomorphine (aka “krokodil”). Testing during this phase of the 

project involved trace residues and bulk powder of precursors and illicit products, and potential 

solvents used in clandestine operations were examined via APCI-MS (see Section 3.3 for 

discussion of this ionization source). The AI-MS 1.2 was also shown able to monitor both the 

Birch reduction and Nagai synthetic routes for methamphetamine, identifying both precursor and 

product species at any point during the reactions. 

General Screening

(Base MS)

Detection?

Automated MS/MS Confirmation

Confirmed?

Yes

Yes

No

No

Document/Collect As Essential Evidence

Clean Source And Run Blank

Software Indicates 

“Warning”

Software 

“Alarms”

Present Sample

After Completion

Collect As Non- Essential Evidence

Warning or Alarm?

No Yes

Figure 3-30. Proposed flow of experiment for a typical DESI-MS 

analysis on the Flir AI-MS 1.2 utilizing the Level 1 protocol. 

Samples will be initially screened to see if base MS spectra 

obtained match any target analytes in the database, with possible 

matches indicated by the software as a yellow “warning.” 

Automated MS/MS confirmation of said warnings is then 

completed by the instrument, and if a fragmentation spectral match 

is obtained, the instrument software will “alarm” for the presence 

of the analyte. This iterative process continues for a pre-set limit 

(4 min.), after which analysis ends and all warnings/alarms are 

indicated to the user. Confirmed and non-essential evidence can 

then be documented at the scene and transported to off-site labs for 

further confirmation or storage. After cleaning the ionization 

source to limit cross-contamination, a new sample can be 

presented for analysis.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
48

3.5.1 Identification of Common Tablets and Powdered Precursors for Methamphetamine 

Production 

In regards to synthetic methamphetamine production, two of the most common 

precursors, ephedrine and pseudoephedrine (isomeric compounds), can be purchased in limited 

supply as active ingredients in over-the-counter pharmaceuticals, meaning that corresponding 

forensic evidence could be found unlabeled as loose tablets, pulverized powder, or extracts (i.e. 

solution-phase). DESI-MS was successfully used to identify both ephedrine and 

pseudoephedrine as residues (by direct analysis of the substrate), as a solution (by spotting and 

drying onto a substrate), and also as a component of crushed pharmaceutical tablets. 

For the analysis of pulverized tablets, the user can proceed in two ways: deposition of the 

powder onto an adhesive-backed glass slide or sampling with a surface swab, both subsequently 

analyzed directly via DESI-MS. Figure 3-31 shows the DESI-MS spectrum collected from a 

swab used to sample a pulverized Advil Allergy and Sinus tablet, readily showing the expected 

spectral profiles for pseudoephedrine and ibuprofen, two active ingredients found in the tablet. 

Figure 3-32 shows a photo depicting the swabbing aspects of this experiment. For these studies, 

the surface swab protocol discussed in Section 3.2.2 was used.

 

Figure 3-31. DESI-MS from a swab used to sample a 

pulverized Advil Allergy and Sinus tablet. Spectral 

signatures for both pseudoephedrine and ibuprofen (both 

active ingredients) are readily seen.

Figure 3-32. Photo showing the swab 

sampling of pulverized pharmaceutical tablets. 

The swab can be subsequently analyzed via 

DESI-MS. 

As manufacturers begin and continue to substitute phenylephrine in place of 

pseudoephedrine in allergy medications, pharmacies have recently begun selling allergy 

medications without restrictions while further restricting or discontinuing the sale of the original 

formulations commonly acquired for the purpose of clandestine methamphetamine synthesis. 

Due to the ease of purchase and general misinformation, clandestine laboratory operators may 

accidentally purchase and utilize these newer formulations, causing forensic evidence from a 

suspected site to contain phenylephrine. To demonstrate the ability to perform both trace and 

bulk-level detection of this analyte with the Flir AI-MS 1.2, bulk phenylephrine hydrochloride 

powder was purchased from Sigma-Aldrich and used to make standard solutions for 

characterization or analyzed as-is. As seen in Figure 3-33, DESI-MS spectra for phenylephrine 

exhibit a base peak for the protonated molecule at m/z 168 and an in-source fragment at m/z 150, 

0

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90 140 190 240 290 340 390 440 Ion Intensity

m/z

166 [Pseudoephedrine+H]+

161[Ibuprofen–COOH]+

148 [Pseudoephedrine–OH]+

207 [Ibuprofen+H]+

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
49

corresponding to the loss of water. MS/MS of the m/z 150 fragment (seen in Figure 3-33B) 

yields signatures at m/z 91, 109, 119, and 135 through a series of complex, gas-phase 

rearrangements. The similarity of this fragmentation data to that of methamphetamine is of 

concern, and was a focus of our databasing efforts discussed in Section 3.1.7 and 3.4.2.

 

Figure 3-33. (A) DESI-MS data collected for phenylephrine, with MS/MS data for m/z 168 protonated 

molecule inset. (B) MS/MS data for m/z 150 in-source fragment with molecular assignment.

Additionally, mass spectra were obtained for two different formulations of over-thecounter allergy medications, CVS Sinus Headache PE Non-Drowsy caplets (containing 

acetaminophen and 5 mg phenylephrine per capsule) and CVS Non-Drowsy Non-Drying Sinus 

PE Maximum Strength (containing guaifenesin and 5 mg phenylephrine), to simulate 

medications with potential of being misued for clandestine methamphetamine production. A 

small section of each pill was ground into a fine powder and sampled via a sampling swab prior 

to DESI-MS anlaysis. Figure 3-34 shows data for the guaifenesin-containing (34A) and 

acetaminophen-containing (34B) tablets, yielding intense spectral signatures for all active 

ingredients, including the inherent phenylephine. 

Figure 3-34. (A) DESI-MS spectrum of a pulverized CVS Non-Drowsy Non-Drying Sinus PE Maximum Strength

tablet, showing phenylephrine signatures at m/z 168 and 150, as well as two distinct guaifenesin species, [M+H]+

and [M+Na]+, at m/z 199 and 221, respectively. Corresponding MS/MS of the guaifenesin precursor is inset. (B) 

DESI-MS spectrum of a pulverized CVS Sinus Headache PE Non-Drowsy tablet, showing phenylephrine and the 

acetaminophen parent at m/z 152. Corresponding MS/MS of the acetaminophen precursor is inset.

3.5.2 Detection of Methamphetamine Residue from Production and Storage Media 

 To determine if a clandestine laboratory is truly being used for meth production (as 

opposed to crack cocaine conversion or fentanyl synthesis), detection of powdered 

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This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
50

methamphetamine and its residues is necessary. To show application to this need, the ability to 

swab various substrates found in clandestine lab scenarios for meth residues and verify their 

presence with the Flir AI-MS 1.2 was demonstrated. For this testing, various materials were 

spotted with a known mass of methamphetamine standard, probed via sampling swab following 

the protocol discussed in Section 3.2.2, and analyzed by direct DESI-MS analysis of the swab 

surface. Table 3-6 shows the detection limit from these methamphetamine residue studies, 

proving that trace residues can be successfully swabbed, transferred and identified. While there 

are a multitude of other potential surfaces of interest that can be found in these locations, they are 

expected to be applicable to our swab transfer protocol, producing variable detection limits 

depending on the characteristics of the substrates themselves. Residues of the emerging drug 

desomorphine and its codeine precursor were also shown applicable to our swab transfer 

protocol, discussed further in Section 3.5.4. 

Table 3-6. Detection Limit for Methamphetamine 

Residues from Surfaces of Interest 

3.5.3 Monitoring the Clandestine Synthesis of Methamphetamine via Ambient MS 

The Flir AI-MS 1.2 was successful in proof-of-principle screening of the most common 

methamphetamine precursors, ephedrine and pseudoephedrine, as residues, solutions, and 

components of crushed pharmaceutical tablets, as well as methamphetamine itself. To 

demonstrate this capability in a real setting, we participated in the Clandestine Lab Safety 

Certification course offered through the Midwest Counterdrug Training Center (MCTC) in July 

2013 (Camp Dodge, IA). Under the observation of U.S. Drug Enforcement Agency 

representatives, we had the opportunity to sample, analyze and monitor authentic clandestine 

methamphetamine syntheses, as well as demonstrate the capabilities of the Flir AI-MS 1.2 

instrumentation to practitioners in law enforcement and forensics. Representatives from the 

Army/National Guard, Iowa State Police, Drug Enforcement Agency, and state and local law 

enforcement from across the U.S. were in attendance at this course. 

During this course, clandestine production of methamphetamine was demonstrated using 

two common synthetic pathways, the Birch and Nagai (red phosphorous) methods, which both 

utilized pseudoephedrine as a precursor. After successful instrument setup, calibration and 

tuning, DESI and PSI-MS was utilized to analyze each significant step in the synthetic pathways. 

A schematic representation of each synthesis and the success of either DESI or PSI-MS analysis 

at each procedural step in seen in Figure 3-35. 

Surface Detection Limit

Aluminum Foil 500 ng

Carbon Steel 500 ng

Glass 2 μg

Polypropylene 

Bottle 5 μg

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
51

Figure 3-35. Schematic representation of the Birch and Nagai syntheses for clandestine 

methamphetamine production that were monitored by the Flir AI-MS 1.2 system via DESI or PSI-MS. 

Green checkmarks correspond to a library match for target compounds. Red crosses correspond to 

inconclusive data. N/A indicates that analysis at this step was not completed or not possible.

These data represent a crucial achievement for the instrument, as each synthesis can be 

sufficiently monitored in real-time, showing the consumption of the pseudoephedrine precursor, 

production and extraction of free-base methamphetamine, and filtration of methamphetamine 

HCl crystals, all while being fairly robust to the harsh nature of the reaction vessel. This, in 

essence, allows the Flir AI-MS 1.2 to conclusively identify a clandestine methamphetamine 

operation regardless of synthesis stage. As seen, the Birch synthesis is thoroughly examined, 

while testing was a bit more selective with the Nagai synthesis. Since reaction sampling was 

taking place in conjunction with the regular course instruction, access to the Nagai synthesis was 

more constrained. 

The spectral data that follows represents that obtained during the entire monitoring 

process. Exact detail of each step of the synthesis is not given in an effort to deter the 

publication of detailed procedure of methamphetamine production to the general public. 

Monitoring of the Birch Synthesis 

1) Preparation of Pseudoephedrine 

The Birch synthesis utilized reagent-grade pseudoephedrine that required no purification. 

PSI detection of pseudoephedrine was achieved by swabbing loose powder with a paper triangle. 

DESI detection of pseudoephedrine was achieved by using a spatula to adhere a small quantity of 

loose powder to a glass slide with double-sided tape. The PSI-MS and DESI-MS data obtained 

for pseudoephedrine are represented in Figure 3-36.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
52

Figure 3-36. PSI-MS and DESI-MS spectra obtained for the pseudoephedrine precursor. (A) PSI-MS 

spectrum of pseudoephedrine powder collected with a triangular piece of chromatography paper. (B) 

DESI-MS spectrum of pseudoephedrine powder deposited on a glass slide covered with double-sided 

tape. The protonated ion of pseudoephedrine and its in-source fragment via loss of water can be seen in 

both spectra at m/z 166 and 148, respectively. 

2) Birch Reduction to Methamphetamine 

PSI detection of methamphetamine and residual pseudoephedrine was achieved through 

use of a disposable glass pipet to sample the aqueous layer and spot a small amount upon a paper 

triangle. DESI detection of both methamphetamine and residual pseudoephedrine was achieved 

by spotting a portion of the aqueous layer upon a printed Teflon slide. 

3) Extraction of Methamphetamine Base 

Addition of Coleman Fuel to the round bottom flask forms an immiscible organic layer to 

which methamphetamine migrates via liquid-liquid extraction. PSI and DESI detection of 

methamphetamine was achieved through pipetting and spotting a portion of the organic layer 

upon the same substrates used in the previous step. Pseudoephedrine was detected at low 

intensity for both ionization methods. 

 To demonstrate the detection of potential solvents utilized in clandestine 

methamphetamine production, vapor from the Coleman Fuel container was transferred and 

analyzed via APCI with our supplemental pumping system described in Section 3.3. Direct 

analysis of the vapor produced fairly complex, yet characteristic, APCI mass spectra, seen in 

Figure 3-37. The data is marked by broad hydrocarbon peaks with noticeable species at m/z 85, 

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148

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148 166

A

B

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
53

113, 127, and 129, with 127 and 129 tentatively assigned to [Naphthalene - H]+ and 

[Naphthalene + H]+.

Figure 3-37. APCI mass spectrum of Coleman Fuel vapor, displaying a 

characteristic hydrocarbon envelope and peaks suggestive of naphthalene.

4) Crystallization as Methamphetamine HCl 

5) Filtration of Product Crystals 

A standard coffee filter was used to filter the methamphetamine HCl crystals from the 

organic layer. After filtration, the crystals were washed with acetone to remove any remaining 

impurities and to aid in drying; acetone vapor was also detected and confirmed via APCI (data 

not shown). Detection of methamphetamine via DESI was achieved by transferring powderized 

crystals to double-sided tape adhered to a glass slide, shown in Figure 3-38A. Methamphetamine 

was also detected with DESI by sampling the product crystals using a nonwoven swab, with 

pseudoephedrine visible at noise level. Methamphetamine was also detected via PSI by directly 

swabbing the dried product crystals, with low intensity pseudoephedrine visible, as represented 

in Figure 3-38B. PSI swabbing of damp crystals produced inconclusive spectra due to low 

analyte transfer. 

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Intensity

m/z

113

127 [Naphthalene - H]+

129 [Naphthalene + H]+

85

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
54

Figure 3-38. DESI-MS and PSI-MS spectra of filtered methamphetamine crystals. (A) DESI-MS 

spectrum of methamphetamine crystal powder deposited on a glass slide equipped with doublesided tape; this is depicted in the enclosed photograph. Methamphetamine is seen at m/z 150, 

119 and 91, while pseudoephedrine is seen at m/z 166 and 148. (B) DESI-MS/MS spectrum 

resulting from the m/z 150 precursor. (C) PSI-MS spectrum of swabbed methamphetamine 

crystals. (D) PSI-MS/MS spectrum resulting from the isolation and fragmentation of m/z 150. 

Monitoring of the Nagai (Red Phosphorous) Method 

1) Preparation of Pseudoephedrine 

This synthesis utilized the same reagent-grade pseudoephedrine. DESI and PSI-MS 

analysis was conducted in the same manner as with the Birch synthesis. 

2) Nagai Reduction to Methamphetamine 

To support the ability of the Flir Systems AI-MS 1.2 to analyze highly acidic solutions 

while protecting its critical components, a filter paper swab was used to collect a sample of the 

contents present in the round bottom flask during the Nagai reduction. Figure 3-39 shows the 

PSI mass spectrum resulting from the direct analysis of the swab, which also acted as the 

substrate for ionization. PSI has been shown more apt at minimizing exposure of the Flir AI-MS

1.2 inlet system to harsh samples; DESI-MS of surface-bound samples has a tendency of 

transferring a majority of the sample matrix along with the analyte of interest, while the PSI 

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Absolute Intensity

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150

A B

C D

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
55

substrate has a tendency to retain it. To this end, PSI was used more extensively to monitor the 

overall Nagai synthesis. 

Figure 3-39. PSI-MS spectrum of the contents present in the round bottom flask (photo inset) during 

Nagai reduction. The molecular ion of methamphetamine is seen at m/z 150, with characteristic in-source 

fragments present at m/z 119 and m/z 91. Likewise, the molecular ion of pseudoephedrine can be seen at 

m/z 166, with a characteristic in-source fragment at m/z 148. 

3) Neutralization of Remaining Acid 

4) Extraction of Methamphetamine Base 

PSI detection of freebase forms of methamphetamine and pseudoephedrine was achieved 

by spotting a portion of reaction mixture to filter paper with a disposable pipet. 

5) Crystallization as Methamphetamine HCl 

6) Filtration of Product Crystals 

A coffee filter was used to filter the methamphetamine as in the Birch method. PSI 

spectra obtained from swabbing dried crystals exhibited methamphetamine, with 

pseudoephedrine near noise level. Interestingly, PSI was able to be performed by directly 

spraying from a triangular piece of the coffee filter that was used in the filtration process. For 

this, a triangular piece was cut from the coffee filter and directly placed in our PSI ionization 

source. The PSI-MS spectrum directly from the coffee filter is shown in Figure 3-40, showing 

methamphetamine and pseudoephedrine signatures. 

0

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50 150 250 350 450

Absolute Intensity

m/z

166

150

119 91

148

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
56

Figure 3-40. PSI-MS spectrum obtained from directly spraying from a triangular section of coffee filter 

utilized in the filtration process (representative photo inset). Spectral signatures confirm the presence of 

both methamphetamine product and unreacted pseudoephedrine precursor. 

3.5.4 Analysis of Desomorphine, Codeine and Fentanyl 

The use of the drug desomorphine (street name "krokodil”) has been seen in Europe, but 

recent reports of its production and use in the U.S. have made it news-worthy. To demonstrate 

desomorphine analysis on the Flir AI-MS 1.2 platform, an analytical standard of this codeine 

derivative was purchased and analyzed via DESI-MS. As seen in Figure 3-41, the generated 

spectra show an intense m/z 272 ion corresponding to protonated desomorphine, while the 

MS/MS of the m/z 272 precursor yields fragments at m/z 215 and 197, corresponding to a loss of 

C4H9 and C4H10O, respectively. 

To demonstrate trace-level detection, residues of desomorphine and its codeine precursor 

were swabbed and subsequently analyzed via DESI-MS from various surfaces of potential use in 

clandestine synthesis, including nonstick coated cookware, enamel cookware, glass, steel, and 

polyethylene terephthalate (PET) pill bottles. The detection limits from these surfaces can be 

seen in Table 3-7, with LODs typically residing in the low microgram range for most surfaces. 

Teflon printed slides produced the lowest detection limit, which is typical from our experience 

with this substrate; the hydrophobicity of Teflon enhances the removal of analyte via the solventmediated DESI desorption mechanism. 

Clandestine production of desomorphine involves the derivatization of codeine, and 

given the relative ease of acquiring codeine via prescription pills and cough syrups compared to 

the availability of ephedrine/pseudoephedrine needed for clandestine methamphetamine 

production, there is legitimate concern of an uptick of desomorphine use and production. To this 

end, experimentation on codeine-containing prescription pills was undertaken. Figure 3-42 

shows the DESI-MS spectrum collected from a swab brought into contact with a pulverized 

tablet of Tylenol 3 (active ingredients: acetaminophen (300 mg) and codeine phosphate (30mg)). 

As seen, the spectra feature strong peaks for the active ingredients of the pill with minimal 

background. MS/MS of the codeine precursor (inset) produces similar fragments reported in 

literature and also seen in past Flir AI-MS 1.2 characterization. 

0

75

150

225

300

50 150 250 350 450

Absolute Intensity

m/z

150

148

119

166

91

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
57

Figure 3-41. DESI-MS and MS/MS (inset) spectra of desomorphine, showing 

the protonated molecule, [M+H]+, at m/z 272 and fragments at m/z 215 and 197.

Table 3-7. LODs of desomorphine and codeine from surfaces of interest 

LOD

Surface Desomorphine Codeine

Steel 3.0 μg 5.0 μg

Nonstick cookware 2.5 μg 2.0 μg

Enamel cookware 1.0 μg 4.5 μg

PET bottle 1.5 μg 3.0 μg

Glass 1.0 μg 5.0 μg

Teflon Slide 0.50 ng 0.90 ng

Figure 3-42. DESI-MS spectrum of Tylenol 3 powder from a foam swab. MS/MS of 

the codeine precursor (inset) matches past data in our spectral database.

0

500

1000

1500

2000

2500

3000

50 150 250 350 450

Intensity

m/z

0

50

100

150

200

100 200 300

272

272

272 215

197

0

500

1000

1500

2000

2500

3000

3500

50 150 250 350 450

300 183

225

243

215

152 300

300

[Acetaminophen + H]+

[Codeine + H]+

0

50

100

150

100 200 300

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
58

 It is expected that, given the broad applicability demonstrated in regards to both drug 

classes and states they reside in, ambient ionization methods coupled to the Flir AI-MS 1.2 will 

be capable to detect target species in other known and emerging clandestine syntheses. For 

instance, initial studies involving fentanyl shows high sensitivity analysis of its residues via 

DESI-MS. Representative fentanyl data can be seen in Figure 3-43. 

Figure 3-43. DESI-MS and MS/MS (inset) data collected for fentanyl residue from a glass slide 

collected on the Flir AI-MS. Aspects of this data were sent for comparison to the MSforID 

database. 

3.6 Task 6: Conduct Field Experiments and Disseminate Findings to Practitioners 

While many of the results obtained on the Flir AI-MS 1.2 during this project involved 

analytical standards in controlled laboratory settings, special efforts were taken to perform field 

testing on authentic forensic evidence. Field testing with law enforcement, forensics and 

criminal justice practitioners serves dual purposes, as the effect of environmental variables (i.e.

transport and calibration, ambient conditions, etc.) can be assessed while gathering integral 

feedback from the target user groups. Overall, practitioners who witnessed our demonstrations 

and field experimentation were impressed by the performance of the Flir AI-MS 1.2, size of the 

device, and especially by the ease of use. Through discussion with these groups, information 

regarding needs for true field implementation and use by untrained personnel was acquired that 

helped craft and improve our developed methods and ionization source design. Furthermore, 

important troubleshooting experiences can arise in the field. 

3.6.1 Synthetic Cathinone “Bath Salt” Evidence 

Trace analysis of drug of abuse residues is an important ability and has been shown 

repeatedly on the AI-MS 1.2, but the capability to look at condensed phases like powders and 

tablets from drug seizures is just as much of a necessity. Through collaboration with the 

Bloomington Police Department Vice Squad (Bloomington, IL), access to authentic synthetic 

0

50

100

150

200

250

300

50 100 150 200 250 300 350 400 450

Ion Intensity

m/z

[Fentanyl+H]

+

337

0

5

10

15

20

25

30

50 150 250 350 450

188 [Fentanyl- C6H5NCOCH2CH3]

+

337

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
59

cathinone “bath salt” powders that were seized as commercially-available products at local 

retailers was provided to test screening capability via DESI-MS. These seizures were confirmed 

positive for their associated illicit drugs via GC-MS analysis through the Illinois State Police 

forensic laboratory system prior to our analyses. Packaging for these evidentiary samples can be 

in seen in Figure 3-44, advertised under names such as White Lace, White Horse, and Global 

bath salts, Global plant food, and Disco all-purpose solution. Figure 3-45 shows representative 

consistency of select compositions. 

Figure 3-44. Packaging of the seized bath salt products provided through the Bloomington (IL) Police

Department. These commercial products were seized or voluntarily forfeited from local retailers in the 

Bloomington-Normal, IL area. (A) Global Plant Food. (B) White Lace Bath Salt. (C) Global Bath Salts. 

(D) DISCO All-Purpose Solution. (E) Down2Earth White Horse Concentrated Bath Salt – front of 

packaging. (F) Down2Earth White Horse Concentrated Bath Salt – back of packaging.

Figure 3-45. Photos showing the consistency of select bath salts that were analyzed. LEFT: Pill capsule 

containing illicit bath salts. Capsule was opened and powder substance was deposited onto double-sided 

adhesive tape and directly analyzed via DESI-MS. RIGHT: Most of the seizures were packaged as loose 

powders. These powders were deposited onto double-sided adhesive tape and directly analyzed with 

DESI-MS. 

A B

C D

E Front

F Back

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
60

To allow direct detection of these powders with minimal sample preparation, a piece of 

Scotch® Double-Sided tape adhered to a glass microscope slide was used as the analysis surface. 

A small amount (~1 mg) of the powder evidence was then deposited onto the tape, using a 

spatula to break up larger clumps and force contact between the powder and adhesive (as 

depicted in Figure 3-46C). To prevent sample carryover, loose powder was removed from the 

surface of the tape using a light flow of compressed air prior to DESI analysis. Of note, no 

carryover was seen sample-to-sample for this powder analysis method. 

Figure 3-46A shows the positive ion DESI mass spectrum of a seizure determined 

positive for the presence of MDPV, yielding an intense spectral peak for the protonated molecule 

at m/z 276. MS and MS/MS analyses of this seizure directly matched data collected with 

analytical standards. Besides the more common cathinones like MDPV, pentedrone, an analogue 

of methcathinone, was also present in select samples. Figure 3-46B shows the analysis of 

powdered pentedrone, yielding the protonated molecule at m/z 192 and an in-source fragment at 

m/z 174, corresponding to loss of water. The corresponding MS/MS confirmation of the 

protonated molecule precursor can be seen in the inset, showing both the in-source fragment seen 

in MS mode and other transitions consistent to those reported in literature. The simple 

preparation utilized for the powdered bath salts can be extended to other powdered drugs of 

abuse that have been previously investigated as tablets with DESI-MS. 

Figure 3-46. DESI-MS data collected on the Flir AI-MS 1.2 from authentic powdered bath salt evidence. 

(a) Evidence positive for MDPV shows the protonated molecule at m/z 276. (b) Evidence positive for 

pentedrone shows the protonated molecule and in-source fragment at m/z 192 and 174, respectively. (c) 

By simple deposition onto double-sided adhesive tape, powdered evidence can be rapidly analyzed with 

no significant carryover.38

0

20

40

60

80

100

50 100 150 200 250 300 350 400 450

276

Relative Abundance

A

m/z

[MDPV + H]+

0

20

40

60

80

100

50 100 150 200 250 300 350 400 450

192

174

[Pentedrone + H]+

0

50

100

100 150 200 250

192

174

161

132

192

B

C

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
61

 

While at Camp Dodge, IA completing the Clandestine Lab Safety Certification course, 

there was significant opportunity to discuss facets of our NIJ-funded research and the 

instrumentation being developed. Helpful discussions regarding needs for true field 

implementation and use by untrained personnel conducted during this opportunity will help 

guide our continued work on the Flir AI-MS 1.2 system. Through law enforcement contacts, we 

were also able to further demonstrate and conduct field experiments on authentic evidence 

provided by the Iowa State Police. 

3.6.2 Powder and Residue-Level Cocaine and Methamphetamine Evidence 

In cooperation with the Iowa State Police, 

experimentation on authentic drug evidence, specifically bulk 

cocaine powder (Figure 3-47) and trace residues of 

methamphetamine, was conducted. In fact, the 

methamphetamine evidence that was provided was actually just 

a plastic bag used to transport the drug, containing an extremely 

small crystal that could barely be seen with the naked eye. To 

analyze this sample via DESI-MS, the remaining crystal was 

dissolved in a small aliquot of methanol and subsequently 

spotted and analyzed. 

Characteristic data for both PSI and DESI-MS were able 

to be obtained from each evidence type. Figure 3-48 shows the 

PSI-MS and MS/MS mass spectra collected from swabbing the 

inside of the bag known to previously transport crystal 

methamphetamine. The PSI-MS mass spectrum, collected from the transfer swab itself, not only 

displays the molecular ion of methamphetamine at m/z 150, but also the characteristic in-source 

fragments at m/z 119 and 91. Of significance is the high intensity obtained, suggesting that an 

even smaller amount of methamphetamine could have been successfully detected. This is an 

interesting finding, as it supports PSI as a probable method for the detection of extremely trace 

samples. To analyze the bulk cocaine powder via PSI-MS, a paper substrate was first wetted with 

2 μL of methanol to assist in the transfer of the analyte to the swab. The paper itself was dipped 

into the bulk powder, followed by direct PSI analysis. Figure 3-49 shows the PSI-MS and 

MS/MS mass spectrum obtained for the bulk authentic cocaine powder swabbed from the inside 

of a plastic bag. The molecular ion of cocaine is seen at m/z 304 with characteristic MS/MS 

fragments present at m/z 182 and 150. 

Of interest, experimentation with bulk forensic evidence was able to be accomplished 

without extensive carryover between analyses by implementing proper hygiene protocols 

involving cleaning of the ionization source and outer surface of the MS inlet capillary with 

methanol-wetted swabs and analysis of pre-sample blanks. 

Figure 3-47. Photo showing 

powdered cocaine evidence 

provided by the Iowa State 

Police.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
62

Figure 3-48. (A) PSI-MS and (B) MS/MS data collected for authentic methamphetamine residue 

present in a plastic bag using the Flir AI-MS. The sample was dissolved in methanol prior to 

analysis due to the minute amount of sample available for analysis. 

Figure 4-49. (A) PSI-MS and (B) MS/MS data collected from authentic bulk cocaine powder 

using the Flir AI-MS. The sample was collected using a prewetted paper substrate as a surface 

swab.

3.7 Task 7: Preparation of Deliverable Instrument and Associated Documentation 

An important final aspect of this project was to prepare and deliver a modified Flir AIMS 1.2 system coupled with the associated ionization sources investigated. Along with the 

instrumentation, a comprehensive mass spectral library (including MS and MS/MS data for 

project analytes) and optimized compound-specific MS/MS methods were delivered. Also, 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
63

methods allowing automated library searching via data dependent scanning (Level 1 methods, 

see Section 3.4.2) were able to be constructed and delivered. Documentation delivered with the 

Flir AI-MS 1.2 included extensive training and troubleshooting manuals, with substantial detail 

to ensure that NIJ personnel and other users will be able to quickly learn the operation of all 

facets of the system. 

4. Conclusions 

4.1 Discussion of Findings 

The Flir Systems AI-MS 1.2 was demonstrated to be a broadly-applicable, portable 

instrument with high potential for use in crime scene investigation and evidentiary analysis. The 

flexibility to screen and identify solid, liquid and gas-phase analyte when utilizing the suite of 

ionization methods developed and/or investigated on the system has the potential to provide 

capabilities that no other fieldable technology currently available can offer. Switching between 

trace level residues and bulk-level samples was achievable with no carryover when 

implementing simple hygiene protocols, and coupling with physical transfer swabs extends 

application of the system to large and geometrically-complex surfaces, meeting the demands that 

real evidence present. The congruency of spectral data collected on the AI-MS 1.2 in regards to 

both MS and MS/MS ion signatures collected on lab-scale MS instrumentation and also seen in 

scientific literature is seen as important milestone towards acceptance as a validated forensic 

analysis method and actual implementation in CSI applications. 

The only class of forensic evidence where the Flir AI-MS 1.2 failed to meet expectations 

was military grade explosives (e.g. TNT, RDX, HMX and PETN), for which DESI-MS analysis 

is routinely accomplished with lab-scale instrumentation through doping the spray solvent with 

the Cl- anion (commonly from small volumes of HCl or NaCl); these dopants create chloridebound adducts with the analytes. Interestingly, chloride-bound adducts are not observed in 

DESI-MS testing of explosives on the Flir AI-MS 1.2 at any appreciable level. It is expected 

that the optics utilized for ion introduction at the high pressure stages of the system energizes the 

formed adducts and makes them unstable; this also can explain the in-source fragmentation 

observed for other analytes investigated over the project duration. 

4.2 Implications for Policy and Practice

When considering the end product of this project, a portable instrument capable of 

assessing the probative value of physical evidence typically found at crime scenes, the impact of 

providing the forensic science community with said technology would have a positive effect on 

criminal justice practice at the local, state and national level. There are also potential 

implications in regards to reducing evidence backlogs that hinder publicly-funded forensic 

laboratories, as this technology provides both higher throughput and a potentially reduced influx 

of evidence entering the lab system. When considering the feasibility of implementing the 

proposed technology in forensic settings, the cost of this instrumentation and maintenance could 

be off-set by the reduction in evidence sent to forensic laboratories and funds being used for 

outsourced analyses to private laboratories. 

 While the effect on current criminal justice practice can be presumed, the implications on 

current criminal justice policy are not as clear. Field-portable units for accurate contraband 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
64

detection in the condensed phase and from surfaces would allow greater versatility in routine 

traffic stops and criminal investigations, but if this technology is used to gather evidence prior to 

an arrest, there are implications regarding unreasonable search and seizures. It is easy to 

envision using the capabilities of the Flir Systems AI-MS 1.2 to establish “probable cause” in 

innovative ways, especially for residues of contraband in latent fingerprints. Overall, 

implementation of the proposed research could allow greater flexibility in law enforcement, but 

its application to legal convictions under current criminal justice policy will need to be 

considered before common usage. 

When a new technology is proposed for evidence analysis in the criminal justice system, 

there is a level of scrutiny to which the method is held. The Daubert Standard, also known as 

Rule 702 of the Federal Rules of Evidence, provides guidelines for admissible expert testimony 

stemming from a data obtained with new technologies or methods. When this type of expert 

testimony is being dissected, more effort than not is placed into refuting the method in which the 

data was obtained. Our characterization studies on the Flir AI-MS 1.2 allude that this system has 

promise meeting the expectations established by Daubert, particularly in regards to falsifiability 

error rate, but further validation will be needed to satisfy all provisions. 

4.3 Implications for Further Research 

 There are several areas of interest in regards to future research on the Flir AI-MS 1.2 

platform. Particularly, ambient MS ionization methods represent a highly active research area, 

with new methods reported frequently in the chemical literature. Examination of alternate 

ionization sources for use on this platform could lead to broader application and flexibility in 

forensic applications; this is especially true for PSI-MS, which performed well and, in some 

instances, proved superior to DESI-MS in our proof-of-principle testing. The robust nature of 

the developed instrumental methods could also prove useful in field-based toxicological 

assessments and threat detection applications. The Flir AI-MS 1.2 would also benefit from 

extensive validation at actual crime scenes and harsh environments, allowing the ruggedness of 

the system to be tested and effect of long-term field use to be assessed. From the research 

presented herein, the potential impact on the criminal justice system in terms of scientific 

capabilities can be anticipated, but financial implications (both positive and negative) will not be 

known until thorough economic assessment and cost-benefit analyses. 

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Residues and in Authentic Seizures Using a Portable Mass Spectrometer Equipped With 

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6. Dissemination of Research Findings 

Publications 

1) Vircks, K. E.; Mulligan, C. C. Rapid Screening of Synthetic Cathinones as Trace 

Residues and in Authentic Seizures Using a Portable Mass Spectrometer Equipped 

With Desorption Electrospray Ionization. Rapid Commun. Mass Spectrom., 2012, 26, 

2665-2672.

2) Mulligan, C. C.; Vircks, K. E. Advances in Field-Portable Mass Spectrometers for Onsite Analytics. International News on Fats, Oils, and Related Materials (inform), 2012, 

23, 613-617. 

3) Hall, S. E.; Mulligan, C. C. Application of Ambient Sampling, Portable Mass 

Spectrometers Toward On-Site Screening of Clandestine Drug Operations. For the 

“Current Trends in Mass Spectrometry” Supplement for LCGC North America, Oct. 

2014, s8-s13. 

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
68

4) O’Leary, A. E.; Oberacher, H.; Hall, S. E.; Mulligan, C. C. Combining a Portable 

Tandem Mass Spectrometer with Automated Library Searching - An Important Step 

Towards Streamlined, On-Site Identification of Forensic Evidence. Anal. Methods, 

2014, accepted for publication.

5) Hall, S. E.; O’Leary, A. E.; Lawton, Z. E.; Mulligan, C. C. Analysis of Desomorphine 

with an Ambient Sampling, Portable Mass Spectrometer. Sci. Justice. 2014, in 

preparation

Presentations by Project Personnel at Scientific Conferences/Meetings 

1) Vircks, K. E.; Wieland, J. R.; Mulligan. C. C. Portable Mass Spectrometers Capable of 

Direct Sample Analysis: Characterization and Implication of Usage in Forensic 

Science. 41st Annual Meeting of the Midwestern Association of Forensic Scientists, 

Milwaukee, WI, Sept. 24th– 28th, 2012. 

2) Mulligan, C. C.; Vircks, K. E.; O’Leary, A. E.; Accessing the Probative Value of 

Forensic Evidence with a Ruggedized, Portable Mass Spectrometer Capable of 

Ambient Ionization. 39th Meeting of the Federation of Analytical Chemistry and 

Spectroscopy Societies, Kansas City, MO, Sept. 30th– Oct. 5th, 2012. 

3) Vircks, K. E.; O’Leary, A. E.; Mulligan, C. C. Forensic Applications of a Portable 

Mass Spectrometer. 39th Meeting of the Federation of Analytical Chemistry and 

Spectroscopy Societies, Kansas City, MO, Sept. 30th– Oct. 5th, 2012. 

4) Mulligan, C. C. Invited contributor to NSF-sponsored workshop: Strengthening 

Forensic Science Through Connections with the Analytical Sciences, Arlington, VA, 

Dec. 3rd - 4

th, 2012. 

5) Hall, S. E.; O’Leary, A. E.; Vircks, K. E.; Mulligan, C. C. Using a Portable Mass 

Spectrometer for Direct Screening of Arson and Clandestine Drug Laboratory 

Evidence. 61st ASMS Conference on Mass Spectrometry and Applied Topics, 

Minneapolis, MN, June 9th– 13th, 2013.

6) Mulligan, C. C.; Hall, S. E.; O’Leary, A. E.; Vircks, K. E.; Wieland, J. R. Towards a 

Versatile Mass Spectrometric Platform for Comprehensive Crime Scene Analytics. 61st

ASMS Conference on Mass Spectrometry and Applied Topics, Minneapolis, MN, June 

9

th

– 13th, 2013.

7) Mulligan, C. C. Towards a Versatile Mass Spectrometric Platform for Comprehensive 

Field Analytics. Invited seminar at Indiana State University, Terre Haute, IN, Sept. 

2013.

8) Mulligan, C. C.; O’Leary, A. E.; Hall, S. E.; Wieland, J. R.; Gizzi, M. C. Portable MS 

Systems for Rapid Screening of Forensic Evidence at Clandestine Drug Operations. 

62nd ASMS Conference on Mass Spectrometry and Applied Topics, Baltimore, MD.

2014.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
69

9) O’Leary, A. E.; Hall, S. E.; Oberacher, H.; Mulligan, C. C. Comparison of Forensic 

Tandem Mass Spectral Data Obtained on Portable Instrumentation to an Established 

Reference Library. 62nd ASMS Conference on Mass Spectrometry and Applied Topics, 

Baltimore, MD. 2014.

10) Swiontek, A. I.; Hall, S. E.; O’Leary, A. E.; Mulligan, C. C. Establishing a Surface 

Swabbing Protocol Compatible with Ambient Sampling Mass Spectrometers for OnSite Forensic Evidence Screening. 62nd ASMS Conference on Mass Spectrometry and 

Applied Topics, Baltimore, MD. 2014.

11) Hall, S. E.; O’Leary, A. E.; Traub, A.; Mulligan, C. C. Using an Ambient Sampling, 

Portable Mass Spectrometer for the Direct Analysis of Species Related to 

Desomorphine (“Krokodil”) Synthesis. 62nd ASMS Conference on Mass Spectrometry 

and Applied Topics, Baltimore, MD. 2014.

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
70

Appendix A: Positive-Mode MS and MS/MS Spectral Database 

*Only compounds for which optimized MS/MS parameters were determined have been included 

in this appendix. 

Table of Contents 

A-1. Acetaminophen ......................................................................................................................72

A-2. Alprazolam ............................................................................................................................73

A-3. Amphetamine .........................................................................................................................74

A-4. Benzocaine .............................................................................................................................75

A-5. Benzoylecgonine....................................................................................................................76

A-6. Caffeine..................................................................................................................................77

A-7. Chlorodiazepoxide .................................................................................................................78

A-8. Cocaethylene..........................................................................................................................79

A-9. Cocaine ..................................................................................................................................80

A-10. Codeine ................................................................................................................................81

A-11. Creatine ................................................................................................................................82

A-12. Desomorphine ......................................................................................................................83

A-13. Dextromethorphan ...............................................................................................................84

A-14. Diazepam .............................................................................................................................85

A-15. Dimethyl Phthalate ..............................................................................................................86

A-16. Diphenylamine .....................................................................................................................87

A-17. Diphenhydramine ................................................................................................................88

A-18. Ecgonine Methyl Ester ........................................................................................................89

A-19. Ethyl Centralite ....................................................................................................................90

A-20. Fentanyl ...............................................................................................................................91

A-21. Flunitrazepam ......................................................................................................................92

A-22. Heroin ..................................................................................................................................93

A-23. Hydrocodone........................................................................................................................94

A-24. Hydromorphone ...................................................................................................................95

A-25. Hydroxyzine ........................................................................................................................96

A-26. Ketamine ..............................................................................................................................97

A-27. Levamisole ...........................................................................................................................98

A-28. Lidocaine .............................................................................................................................99

A-29. Lorazepam .........................................................................................................................100

A-30. LSD ....................................................................................................................................101

A-31. MDMA ..............................................................................................................................102

A-32. MDPV ................................................................................................................................103

A-33. Mescaline ...........................................................................................................................104

A-34. Methadone .........................................................................................................................105

A-35. Methamphetamine .............................................................................................................106

A-36. Methyl Centralite ...............................................................................................................107

A-37. Methylphenidate ................................................................................................................108

A-38. Morphine............................................................................................................................109

A-39. Oxycodone .........................................................................................................................110

A-40. 4-Nitrodiphenylamine ........................................................................................................111

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
71

A-41. 4-Nitrosodiphenylamine ....................................................................................................112

A-42. PCP ....................................................................................................................................113

A-43. Pentedrone .........................................................................................................................114

A-44. Phenacetin ..........................................................................................................................115

A-45. Phenylephrine ....................................................................................................................116

A-46. Phenylpropanolamine ........................................................................................................117

A-47. Pseudoephedrine ................................................................................................................118

A-48. Delta-9-THC ......................................................................................................................119

A-49. Triazolam ...........................................................................................................................120

A-50. Zaleplon .............................................................................................................................121

A-51. Zolpidem ............................................................................................................................122

A-52. Zopicolone .........................................................................................................................123

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
72

A-1. Acetaminophen 

A-1.1. Acetaminophen MS Scan 

A-1.2. Acetaminophen MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

152

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

110

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
73

A-2. Alprazolam 

A-2.1. Alprazolam MS Scan 

A-2.2. Alprazolam MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

309

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

281

274

206 241

165

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
74

A-3. Amphetamine 

A-3.1. Amphetamine MS Scan 

A-3.2. Amphetamine MS/MS Scan 

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

136

0

50

100

150

200

250

300

350

50 125 200 275 350 425

Absolute Intensity

m/z

119

91

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
75

A-4. Benzocaine 

A-4.1. Benzocaine MS Scan 

A-4.2. Benzocaine MS/MS Scan 

0

100

200

300

400

500

600

700

800

900

1000

50 125 200 275 350 425

Absolute Intensity

m/z

166

0

50

100

150

200

250

300

350

400

450

500

50 125 200 275 350 425

Absolute Intensity

m/z

138

120 93

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
76

A-5. Benzoylecgonine 

A-5.1. Benzoylecgonine MS Scan 

A-5.2. Benzoylecgonine MS/MS Scan 

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

290

0

100

200

300

400

500

50 125 200 275 350 425

Absolute Intensity

m/z

168

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
77

A-6. Caffeine 

A-6.1. Caffeine MS Scan 

A-6.2. Caffeine MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

195

0

100

200

300

400

500

600

700

50 125 200 275 350 425

Absolute Intensity

m/z

138

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
78

A-7. Chlorodiazepoxide 

A-7.1. Chlorodiazepoxide MS Scan 

A-7.2. Chlorodiazepoxide MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

300

0

200

400

600

800

1000

1200

1400

1600

1800

50 125 200 275 350 425

Absolute Intensity

m/z

283

241

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
79

A-8. Cocaethylene 

A-8.1. Cocaethylene MS Scan 

A-8.2. Cocaethylene MS/MS Scan 

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

318

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

196

150

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
80

A-9. Cocaine 

A-9.1. Cocaine MS Scan 

A-9.2. Cocaine MS/MS Scan 

0

50

100

150

200

250

300

350

400

50 125 200 275 350 425

Absolute Intensity

m/z

304

0

50

100

150

200

50 125 200 275 350 425

Absolute Intensity

m/z

182

150

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
81

A-10. Codeine 

A-10.1. Codeine MS Scan 

A-10.2. Codeine MS/MS 

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

300

0

20

40

60

80

100

120

50 125 200 275 350 425

Absolute Intensity

m/z

161 243

282

183

215

225

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
82

A-11. Creatine 

A-11.1. Creatine MS Scan 

A-11.2. Creatine MS/MS Scan 

0

50

100

150

200

250

300

350

400

450

500

50 125 200 275 350 425

Absolute Intensity

m/z

132

0

50

100

150

200

250

300

50 125 200 275 350 425

Absolute Intensity

m/z

90

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
83

A-12. Desomorphine 

A-12.1. Desomorphine MS Scan 

A-12.2. Desomorphine MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

272

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

215

197

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
84

A-13. Dextromethorphan 

A-13.1. Dextromethorphan MS Scan 

A-13.2. Dextromethorphan MS/MS Scan 

0

50

100

150

200

250

300

350

400

450

500

50 125 200 275 350 425

Absolute Intensity

m/z

272

0

20

40

60

80

100

120

140

50 125 200 275 350 425

Absolute Intensity

m/z

147

213

215

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
85

A-14. Diazepam 

A-14.1. Diazepam MS Scan 

A-14.2. Diazepam MS/MS Scan 

0

100

200

300

400

500

600

700

800

900

50 125 200 275 350 425

Absolute Intensity

m/z

285

0

50

100

150

200

250

50 125 200 275 350 425

Absolute Intensity

m/z

228

257

222

193

182

154

105

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
86

A-15. Dimethyl Phthalate 

A-15.1. Dimethyl Phthalate MS Scan 

A-15.2. Dimethyl Phthalate MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

50 125 200 275 350 425

Absolute Intensity

m/z

195

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

163

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
87

A-16. Diphenylamine 

A-16.1. Diphenylamine MS Scan 

A-16.2. Diphenylamine MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

50 125 200 275 350 425

Absolute Intensity

m/z

170

0

100

200

300

400

500

600

700

800

900

50 125 200 275 350 425

Absolute Intensity

m/z

92

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
88

A-17. Diphenhydramine 

A-17.1. Diphenhydramine MS Scan 

A-17.2. Diphenhydramine MS/MS Scan 

0

300

600

900

1200

1500

1800

2100

2400

50 125 200 275 350 425

Absolute Intensity

m/z

256

0

100

200

300

400

500

600

50 125 200 275 350 425

Absolute Intensity

m/z

167

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
89

A-18. Ecgonine Methyl Ester 

A-18.1. Ecgonine Methyl Ester MS Scan 

A-18.2. Ecgonine Methyl Ester MS/MS Scan 

0

50

100

150

200

250

50 125 200 275 350 425

Absolute Intensity

m/z

200

0

50

100

150

200

250

300

350

50 125 200 275 350 425

Absolute Intensity

m/z

182

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
90

A-19. Ethyl Centralite 

A-19.1 Ethyl Centralite MS Scan 

A-19.2. Ethyl Centralite MS/MS Scan 

0

100

200

300

400

500

600

700

800

900

50 125 200 275 350 425

Absolute Intensity

m/z

269

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

148

120

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
91

A-20. Fentanyl 

A-20.1. Fentanyl MS Scan 

A-20.2. Fentanyl MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

337

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

188

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
92

A-21. Flunitrazepam 

A-21.1. Flunitrazepam MS Scan 

A-21.2. Flunitrazepam MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

314

0

50

100

150

200

250

300

50 125 200 275 350 425

Absolute Intensity

m/z

286

268

240

211

193

123 165

300

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
93

A-22. Heroin 

A-22.1. Heroin MS Scan 

A-22.2. Heroin MS/MS Scan 

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

370

0

10

20

30

40

50

60

70

80

90

50 125 200 275 350 425

Absolute Intensity

m/z

328

310

268

237

211

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
94

A-23. Hydrocodone 

A-23.1. Hydrocodone MS Scan 

A-23.2. Hydrocodone MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

1800

2000

50 125 200 275 350 425

Absolute Intensity

m/z

300

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

199

225

183

243

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
95

A-24. Hydromorphone 

A-24.1. Hydromorphone MS Scan 

A-24.2. Hydromorphone MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

286

0

100

200

300

400

500

600

700

50 125 200 275 350 425

Absolute Intensity

m/z

211 243

185

229

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
96

A-25. Hydroxyzine 

A-25.1. Hydroxyzine MS Scan 

A-25.2. Hydroxyzine MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

50 125 200 275 350 425

Absolute Intensity

m/z

375

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

201

166

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
97

A-26. Ketamine 

A-26.1. Ketamine MS Scan 

A-26.2. Ketamine MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

238

0

200

400

600

800

1000

1200

1400

1600

50 125 200 275 350 425

Absolute Intensity

m/z

220

179

207

125

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
98

A-27. Levamisole 

A-27.1. Levamisole MS Scan 

A-27.2. Levamisole MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

1800

50 125 200 275 350 425

Absolute Intensity

m/z

205

0

100

200

300

400

500

600

50 125 200 275 350 425

Absolute Intensity

m/z

178

88 145

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
99

A-28. Lidocaine 

A-28.1. Lidocaine MS Scan 

A-28.2. Lidocaine MS/MS Scan 

0

100

200

300

400

500

600

700

800

900

1000

50 125 200 275 350 425

Absolute Intensity

m/z

235

0

50

100

150

200

250

300

350

400

450

50 125 200 275 350 425

Absolute Intensity

m/z

85

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
100

A-29. Lorazepam 

A-29.1. Lorazepam MS Scan 

A-29.2. Lorazepam MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

321

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Aboslute Intensity

m/z

303

275

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
101

A-30. LSD 

A-30.1. LSD MS Scan 

A-30.2. LSD MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

1800

50 125 200 275 350 425

Absolute Intensity

m/z

324

0

100

200

300

400

500

600

700

800

900

1000

50 125 200 275 350 425

Absolute Intensity

m/z

281

251

223

197

208

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
102

A-31. MDMA 

A-31.1. MDMA MS Scan 

A-32.2. MDMA MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

194

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

163

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
103

A-32. MDPV 

A-32.1. MDPV MS Scan 

A-32.2. MDPV MS/MS Scan 

0

100

200

300

400

500

600

700

50 125 200 275 350 425

Absolute Intensity

m/z

276

0

50

100

150

200

250

300

50 125 200 275 350 425

Absolute Intensity

m/z

205

175

126

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
104

A-33. Mescaline 

A-33.1. Mescaline MS Scan 

A-33.2. Mescaline MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

337

0

200

400

600

800

1000

1200

1400

1600

1800

2000

50 125 200 275 350 425

Absolute Intensity

m/z

195

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
105

A-34. Methadone 

A-34.1. Methadone MS Scan 

A-34.2. Methadone MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

310

0

500

1000

1500

2000

2500

3000

50 125 200 275 350 425

Absolute Intensity

m/z

265

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
106

A-35. Methamphetamine 

A-35.1. Methamphetamine MS Scan 

A-35.2. Methamphetamine MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

150

0

100

200

300

400

500

600

50 125 200 275 350 425

Absolute Intensity

m/z

119

91

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
107

A-36. Methyl Centralite 

A-36.1. Methyl Centralite MS Scan 

A-36.2. Methyl Centralite MS/MS Scan 

0

100

200

300

400

500

50 125 200 275 350 425

Absolute Intensity

m/z

241

0

50

100

150

200

250

300

350

400

450

50 125 200 275 350 425

Absolute Intensity

m/z

134

106

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
108

A-37. Methylphenidate 

A-37.1. Methylphenidate MS Scan 

A-37.2. Methylphenidate MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

83

234

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

83

234

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
109

A-38. Morphine 

A-38.1. Morphine MS Scan 

A-38.2. Morphine MS/MS Scan 

0

200

400

600

800

1000

1200

1400

1600

1800

50 125 200 275 350 425

Absolute Intensity

m/z

286

0

50

100

150

200

250

300

350

400

450

50 125 200 275 350 425

Absolute Intensity

m/z

211

229

201

183

173

155

268

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
110

A-39. Oxycodone 

A-39.1. Oxycodone MS Scan 

A-39.2. Oxycodone MS/MS Scan 

0

500

1000

1500

2000

2500

50 125 200 275 350 425

Absolute Intensity

m/z

316

0

500

1000

1500

2000

2500

3000

50 125 200 275 350 425

Absolute Intensity

m/z

298

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
111

A-40. 4-Nitrodiphenylamine 

A-40.1. 4-Nitrodiphenylamine MS Scan 

A-40.2. 4-Nitrodiphenylamine MS/MS Scan 

0

50

100

150

200

250

300

50 125 200 275 350 425

Absolute Intensity

m/z

215

0

20

40

60

80

100

120

140

160

180

200

50 125 200 275 350 425

Absolute Intensity

m/z

198

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
112

A-41. 4-Nitrosodiphenylamine 

A-41.1. 4-Nitrosodiphenylamine MS Scan 

A-41.2. 4-Nitrosodiphenylamine MS/MS Scan 

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

199

0

20

40

60

80

100

120

140

160

180

200

50 125 200 275 350 425

Absolute Intensity

m/z

182

169

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
113

A-42. PCP 

A-42.1. PCP MS Scan 

A-42.2. PCP MS/MS Scan 

0

100

200

300

400

500

600

700

800

900

1000

50 125 200 275 350 425

Absolute Intensity

m/z

244

0

20

40

60

80

100

120

50 125 200 275 350 425

Absolute Intensity

m/z

159

86

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
114

A-43. Pentedrone 

A-43.1. Pentedrone MS Scan 

A-43.2. Pentedrone MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

192

0

500

1000

1500

2000

2500

3000

3500

50 125 200 275 350 425

Absolute Intensity

m/z

174

161

132

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
115

A-44. Phenacetin 

A-44.1. Phenacetin MS Scan 

A-44.2. Phenacetin MS/MS Scan 

0

50

100

150

200

250

300

350

50 125 200 275 350 425

Absolute Intensity

m/z

180

0

50

100

150

200

250

50 125 200 275 350 425

Absolute Intensity

m/z

110

132

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
116

A-45. Phenylephrine 

A-45.1. Phenylephrine MS Scan 

A-45.2. Phenylephrine MS/MS Scan 

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

168

0

100

200

300

400

500

600

700

800

50 125 200 275

Absolute Intensity

m/z

150

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
117

A-46. Phenylpropanolamine 

A-46. Phenylpropanolamine MS Scan 

A-46.2. Phenylpropanolamine MS/MS Scan 

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

152

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

134

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
118

A-47. Pseudoephedrine 

A-47.1. Pseudoephedrine MS Scan 

A-47.2. Pseudoephedrine MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

166

0

200

400

600

800

1000

1200

50 125 200 275 350 425

Absolute Intensity

m/z

148

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
119

A-48. Δ-9-THC 

A-48.1. Δ-9-THC MS Scan 

A-48.2. Δ-9-THC MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

315

0

100

200

300

400

500

600

700

50 125 200 275 350 425

Absolute Intensity

m/z

259 221

207

193

181

135

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
120

A-49. Triazolam 

A-49.1. Triazolam MS Scan 

A-49.2. Triazolam MS/MS Scan 

0

100

200

300

400

500

600

700

800

900

50 125 200 275 350 425

Absolute Intensity

m/z

343

0

100

200

300

400

500

600

700

50 125 200 275 350 425

Absolute Intensity

m/z

308

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
121

A-50. Zaleplon 

A-50.1. Zaleplon MS Scan 

A-50.2. Zaleplon MS/MS Scan 

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

306

0

500

1000

1500

2000

2500

3000

3500

4000

50 125 200 275 350 425

Absolute Intensity

m/z

264

288

238

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
122

A-51. Zolpidem 

A-51.1. Zolpidem MS Scan 

A-51.2. Zolpidem MS/MS Scan 

0

50

100

150

200

250

300

350

400

450

500

50 125 200 275 350 425

Absolute Intensity

m/z

308

0

50

100

150

200

250

300

350

400

50 125 200 275 350 425

Absolute Intensity

m/z

235

263

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
123

A-52. Zopicolone 

A-52.1. Zopicolone MS Scan 

A-52.2. Zopicolone MS/MS Scan 

0

200

400

600

800

1000

1200

1400

50 125 200 275 350 425

Absolute Intensity

m/z

389

277

0

100

200

300

400

500

600

700

800

50 125 200 275 350 425

Absolute Intensity

m/z

345

277

245

217

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
124

Appendix B: Negative-Mode MS and MS/MS Spectral Database 

Table of Contents 

B-1. Amobarbital .....................................................................................................................125

B-2. Pentobarbital ....................................................................................................................126

B-3. Phenobarbial ....................................................................................................................127

B-4. Secobarbital .....................................................................................................................128

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
125

B-1. Amobarbital 

B-1.1. Amobarbital MS Scan 

B-1.2. Amobarbital MS/MS Scan 

0

50

100

150

200

250

300

50 125 200 275 350 425

Absolute Intensity

m/z

225

0

20

40

60

80

100

120

140

160

180

200

50 125 200 275 350 425

Absolute Intensity

m/z

182

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
126

B-2. Pentobarbitol 

B-2.1. Pentobarbitol MS Scan 

B-2.2. Pentobarbitol MS/MS Scan 

0

50

100

150

200

250

300

350

400

450

500

50 125 200 275 350 425

Absolute Intensity

m/z

225

0

20

40

60

80

100

120

140

50 125 200 275 350 425

Absolute Intensity

m/z

182

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
127

B-3 Phenobarbitol 

B-3.1. Phenobarbitol MS Scan 

B-3.2. Phenobarbitol MS/MS Scan 

0

20

40

60

80

100

120

140

50 125 200 275 350 425

Absolute Intensity

m/z

231

0

10

20

30

40

50

60

50 125 200 275 350 425

Absolute Intensity

m/z

188

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.
128

B-4. Secobarbitol 

B-4.1. Secobarbitol MS Scan 

B-4.2. Secobarbitol MS/MS Scan 

0

20

40

60

80

100

120

140

160

180

200

50 125 200 275 350 425

Absolute Intensity

m/z

237

0

20

40

60

80

100

120

140

50 125 200 275 350 425

Absolute Intensity

m/z

194

This document is a research report submitted to the U.S. Department of Justice. This report has not 

been published by the Department. Opinions or points of view expressed are those of the author(s) 

and do not necessarily reflect the official position or policies of the U.S. Department of Justice.