Evaluation of Oral Fluid 

Testing Devices

Lorna T. Sniegoski

Jocelyn Waddell

Michael J. Welch

Alim A. Fatah*

National Institute of Standards and Technology

Chemical Science and Technology Laboratory

Coordination by:

U.S. DEPARTMENT OF COMMERCE

*Office of Law Enforcement Standards

National Institute of Standards

and Technology

Gaithersburg, MD 20899–8102

Mae Gackstetter

Robert Q. Thompson

Department of Chemistry

Oberlin College

Oberlin, OH 44074

NISTIR 7585
ABOUT THE LAW ENFORCEMENT AND CORRECTIONS

STANDARDS AND TESTING PROGRAM

The Law Enforcement and Corrections Standards and Testing Program is sponsored by the Office of Science 

and Technology of the National Institute of Justice (NIJ), U.S. Department of Justice. The program responds to the 

mandate of the Justice System Improvement Act of 1979, which created NIJ and directed it to encourage research 

and development to improve the criminal justice system and to disseminate the results to Federal, State, and local 

agencies.

The Law Enforcement and Corrections Standards and Testing Program is an applied research effort that 

determines the technological needs of justice system agencies, sets minimum performance standards for specific 

devices, tests commercially available equipment against those standards, and disseminates the standards and the test 

results to criminal justice agencies nationally and internationally. 

The program operates through:

The Law Enforcement and Corrections Technology Advisory Council (LECTAC) consisting of nationally 

recognized criminal justice practitioners from Federal, State, and local agencies, which assesses technological needs 

and sets priorities for research programs and items to be evaluated and tested.

The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology, which 

develops voluntary national performance standards for compliance testing to ensure that individual items of equipment 

are suitable for use by criminal justice agencies. The standards are based upon laboratory testing and evaluation of 

representative samples of each item of equipment to determine the key attributes, develop test methods, and establish 

minimum performance requirements for each essential attribute. In addition to the highly technical standards, OLES 

also produces technical reports and user guidelines that explain in nontechnical terms the capabilities of available 

equipment.

The National Law Enforcement and Corrections Technology Center (NLECTC), operated by a grantee, which 

supervises a national compliance testing program conducted by independent laboratories. The standards developed by 

OLES serve as performance benchmarks against which commercial equipment is measured. The facilities, personnel, 

and testing capabilities of the independent laboratories are evaluated by OLES prior to testing each item of equipment, 

and OLES helps the NLECTC staff review and analyze data. Test results are published in Equipment Performance 

Reports designed to help justice system procurement officials make informed purchasing decisions.

Publications are available at no charge through the National Law Enforcement and Corrections Technology 

Center. Some documents are also available online through the Internet/World Wide Web. To request a document or 

additional information, call 800 248 2742 or 301 519 5060, or write: 

National Law Enforcement and Corrections Technology Center

P.O. Box 1160

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This document is not intended to create, does not create, and may not be relied upon to create any rights, substantive or 

procedural, enforceable at law by any party in any matter civil or criminal.

Opinions or points of view expressed in this document represent a consensus of the authors and do not represent the 

official position or policies of the U.S. Department of Justice. The products and manufacturers discussed in this 

document are presented for informational purposes only and do not constitute product approval or endorsement by the 

U.S. Department of Justice.

The National Institute of Justice is a component of the Office of Justice Programs, which also includes the Bureau of Justice 

Assistance, the Bureau of Justice Statistics, the Office of Juvenile Justice and Delinquency Prevention, and the Office for Victims of 

Crime.
Evaluation of Oral Fluid 

Testing Devices

Lorna T. Sniegoski

Jocelyn Waddell

Michael J. Welch

Alim A. Fatah 

National Institute of Standards and Technology

Chemical Science and Technology Laboratory

Coordination by:

U.S. DEPARTMENT OF COMMERCE

Office of Law Enforcement Standards

National Institute of Standards

and Technology

Gaithersburg, MD 20899–8102

Mae Gackstetter

Robert Q. Thompson

Department of Chemistry

Oberlin College

Oberlin, OH 44074

 April 2009

U.S. DEPARTMENT OF COMMERCE

Carlos M. Gutierrez, Secretary

NATIONAL INSTITUTE OF STANDARDS

AND TECHNOLOGY

Patrick D. Gallagher, Deputy Director

NISTIR 7585
ACKNOWLEDGMENTS

The technical effort to develop this report was conducted under Interagency Agreement 

2003 IJ R 029, Project No. 08–004.

This research was funded by the National Institute of Justice through the Office of Law

Enforcement Standards (OLES) of the National Institute of Standards and Technology (NIST). 

This report was conducted under the direction of Alim A. Fatah, Program Manager for Chemical 

Systems and Materials, and Mark D. Stolorow, Director of OLES. 
iii

FOREWORD

The Office of Law Enforcement Standards (OLES) of the National Institute of Standards and 

Technology (NIST) furnishes technical support to the National Institute of Justice (NIJ) program 

to strengthen law enforcement and criminal justice in the United States. OLES’s function is to 

develop standards and conduct research that will assist law enforcement and criminal justice 

agencies in the selection and procurement of quality equipment.

OLES is: (1) Subjecting existing equipment to laboratory testing and evaluation, and (2) 

conducting research leading to the development of several series of documents, including 

national standards, user guides, and technical reports.

This document covers research conducted by OLES under the sponsorship of the NIJ.

Additional reports as well as other documents are being issued under the OLES program in the 

areas of protective clothing and equipment, communications systems, emergency equipment, 

investigative aids, security systems, vehicles, weapons, and analytical techniques and standard 

reference materials used by the forensic community.

Technical comments and suggestions concerning this report are invited from all interested 

parties. They may be addressed to the Office of Law Enforcement Standards, National Institute 

of Standards and Technology, 100 Bureau Drive, Stop 8102, Gaithersburg, MD 20899–8102.

 Mark D. Stolorow, Director

 Office of Law Enforcement Standards
iv
v

CONTENTS

FOREWORD................................................................................................................................. iii

COMMONLY USED SYMBOLS AND ABBREVIATIONS..................................................... vii

1. INTRODUCTION ..................................................................................................................1

2. DEVICES FOR TESTING FOR ALCOHOL ........................................................................1

3. DEVICES FOR TESTING FOR DRUGS OF ABUSE........................................................18

3.1 Experimental................................................................................................................18

3.2 Device Testing Results ................................................................................................26

3.3 Interference Testing .....................................................................................................29

3.4 Results from GC/MS Analysis.....................................................................................30

3.5 Summary of Results.....................................................................................................30

TABLES

Table 1. Summary of Results for Qualitative Devices ................................................................13

Table 2. Summary of Results for Qualitative Devices with Potential Interferences...................17

Table 3. Point-of-Collection Drug-Testing Devices to be Analyzed...........................................18

Table 4. Pooled Human Saliva.....................................................................................................18

Table 5. Standard Stock Solutions for Target Analytes...............................................................19

Table 6. Isotopically Labeled Internal Standards for Target Analytes........................................20

Table 7. Set 1 – PCP & Cocaine ..................................................................................................21

Table 8. Set 2 – Codeine & Morphine .........................................................................................21

Table 9. Set 3 – Amphetamine (Amph.) & Methamphetamine (M.Amph.)................................21

Table 10. Set 4 – Carboxy-THC ....................................................................................................22

Table 11. Standard Solutions.........................................................................................................22

Table 12. Over the Counter Drugs.................................................................................................22

Table 13. GC/MS Temperature Parameters and Target Ions for Individual Analytes ..................25

Table 14. Criteria for Oral Fluid Drug Testing Devices................................................................26

Table 15. Limit of Detection for Analytes using Oral Fluid Drug Screen Device ........................27

Table 16. Limit of Detection for Analytes using ORAL SCREEN Saliva 4.................................28

Table 17. Limit of Detection for Analytes using iScreen Oral Fluid Device 6 .............................28

Table 18. Limit of Detection for Analytes using Oratect II...........................................................29

Table 19. Results from Cross Reactivity Testing ..........................................................................30

Table 20. R2 Values and % Recovery for the 7 Analytes..............................................................30

Table 21. Point of Collection Oral Fluid Drug Testing Devices and the Results Shown in 

 Figure 12 ........................................................................................................................39
vi

FIGURES

Figure 1. QED A150 Testing Results..........................................................................................11

Figure 2. Alco-Screen Testing Results ........................................................................................12

Figure 3. QED A150 Intereference Testing Results....................................................................15

Figure 4. Alco-Screen Interference Testing Results....................................................................16

Figure 5. Selected ion Chromatograms by GC/MS for Phencyclidine and Phen-D5-cyclidine...32

Figure 6. Selected ion Chromatograms by GC/MS for Cocaine and Cocaine-D3 ................................. 33

Figure 7. Selected ion Chromatograms by GC/MS for Codeine and Codeine-D3................................. 34

Figure 8. Selected ion Chromatograms by GC/MS for Morphine and Morphine-D3 ......................... 35

Figure 9. Selected ion Chromatograms by GC/MS for Amphetamine and 

 Amphetamine-D5............................................................................................................................................................ 36

Figure 10. Selected ion Chromatograms by GC/MS for Methamphetamine and 

 Methamphetamine-D5................................................................................................................................................. 37

Figure 11. Selected ion Chromatograms by GC/MS for Tetrahydrocannabinol Carboxylic

 Acid and Tetrahydrocannabinol-D3.carboxylic Acid........................................................................... 39

Figure 12. Point of Collection Oral Fluid Drug Testing Devices......................................................................... 39
vii

COMMONLY USED SYMBOLS AND ABBREVIATIONS

A Ampere hf high frequency ohm

ac alternating current Hz hertz p. page

AM amplitude modulation i.d. inside diameter Pa pascal

Amu atomic mass unit in inch Pe probable error

cd Candela IR infrared pp. pages

cm Centimeter J joule Ppm parts per million

CP chemically pure L lambert Qt quart

c/s cycle per second L liter Rad radian

d day lb pound Rf radio frequency

dB decibel lbf pound-force Rh relative humidity

dc direct current lbfin pound-force inch S second

C degree Celsius lm lumen SD standard deviation

F degree Fahrenheit ln logarithm (base e) sec. Section

dia diameter log logarithm (base 10) SWR standing wave ratio

emf electromotive force M molar uhf ultrahigh frequency

eq equation m meter UV ultraviolet

F farad micron V volt

fc footcandle min minute vhf very high frequency

fig. Figure mm millimeter W watt

FM frequency modulation mph miles per hour wavelength

ft foot m/s meter per second wk week

ft/s foot per second mo month wt weight

g acceleration N newton yr year

g gram Nm newton meter

gr grain nm nanometer

H henry No. Number

h hour o.d. outside diameter

area=unit2 (e.g., ft2, in2, etc.); volume=unit3(e.g., ft3, m3, etc.)

PREFIXES (See ASTM E380) COMMON CONVERSIONS

d deci (10-1) da deka (10) 0.30480 m = 1 ft 4.448222 N = 1 lbf

c centi (10-2) h hecto (102) 25.4 mm = 1 in 1.355818 J = 1 ftlbf

m milli (10-3) k kilo (103) 0.4535924 kg = 1 lb 0.1129848 N m = 1 lbfin

μ micro (10-6) M mega (106) 0.06479891g = 1gr 14.59390 N/m = 1 lbf/ft

n nano (10-9) G giga (109) 0.9463529 L = 1 qt 6894.757 Pa = 1 lbf/in2

p pico (10-12) T tera (1012) 3600000 J = 1 kWhr 1.609344 km/h = 1 mph

psi = mm of Hg x (1.9339 x 10-2)

mm of Hg = psi x 51.71

Temperature: T °C = (T °F –32)×5/9 Temperature: T °F = (T °C ×9/5)+32
viii

DISCLAIMER

Certain commercial equipment, instruments, or materials are identified in this paper in order to 

specify the experimental procedure adequately. Such identification is not intended to imply 

recommendation or endorsement by the National Institute of Standards and Technology (NIST), 

nor is it intended to imply that the materials or equipment identified are necessarily the best 

available for the purpose.
1

1. INTRODUCTION

Oral fluid (saliva) testing is becoming increasingly popular as a means for quickly determining if 

someone might be under the influence of drugs or alcohol. Collection of saliva specimens is 

noninvasive, compared to blood and nonintrusive with regards to the privacy of the subject when 

compared to urine collection. In addition, no special facilities or training are required in order to 

obtain the saliva specimen and supervised sample collection eliminates the possibility of sample 

adulteration. Drug detection is possible within a few hours to a full day from initial use, a

timeframe similar to blood samples. The market for these tests is dominated by small, single use

devices. For drugs of abuse testing, the instructions include a disclaimer that a positive use test 

must be confirmed by more rigorous laboratory tests.

NIST undertook a study of oral fluid testing devices for detecting alcohol (ethanol) and for 

detecting common drugs of abuse. This report provides details of the two studies. Five devices 

intended for detecting alcohol in oral fluid were evaluated in terms of their accuracy in detecting 

varying levels of ethanol in oral fluid. The ability of the devices to reliably detect ethanol in the 

presence of potential interfering substances was also assessed. 

Four point-of-collection (POC) devices for detection of drugs of abuse in oral fluid were also 

studied. The ability of the devices to meet the manufacturers’ claims and their practical 

application to detection of drugs of abuse at low concentrations in oral fluid were evaluated. 

Human saliva fortified with known quantities of cocaine, phencyclidine (PCP), codeine, 

morphine, amphetamine, methamphetamine, and (±)-11-nor-9-carboxy-∆

9

-tetrahydrocannabinol 

(carboxy-THC), was used in the analysis. Each device was also tested for cross-reactivity with a 

number of common orally administered, over the counter medications, as well as substances 

which could be expected to occur in human saliva. In general, the POC devices performed close 

to their specifications, with a few exceptions. In some cases, the design of the device could 

make interpretation of the results unreliable or uncertain. 

2. DEVICES FOR TESTING FOR ALCOHOL

2.1 Experimental Procedures for Ethanol-Water Solutions

2.1.1 Preparation of Standard Solutions in Water

Since the legal limit for of-age Driving Under Influence (DUI) in most of the states in the United 

States is 0.080 g ethanol per 100 mL blood (0.080 %), four or five standards with nominal 

concentrations bracketing that value (0.02 % to 0.50 %, mass/volume fraction) were chosen for 

calibration. Nominal concentrations were reported in % (g ethanol per 100 mL water) while 

exact concentration in units of mg ethanol per g solution were plotted and used in data analysis.

Each ethanol and propanol standard solution was prepared in the following manner. An 

appropriate amount of ethanol (99.5 % (mass fraction) purity, Sigma, St. Louis, MO) was added 

to a 250-mL volumetric flask, and the flask was filled with 18 MΩ purified water from a water 

purifier (Barnstead, Dubuque, IA). The masses of ethanol and water were measured on balances 

calibrated with mass standards traceable to NIST. After thorough mixing, 40 mL of the standard 
2

was transferred to a septum-capped vial and stored at 4 °C. 1-propanol was chosen as the 

internal standard, and a 0.10 g per 100 mL water solution was prepared in a similar manner. 

Test solutions were prepared by transferring with a syringe (through the septum cap) 0.5 mL of 

ethanol standard solution (allowed to warm to room temperature) or sample or blank (water) and 

0.5 mL of 1-propanol standard solution (allowed to warm to room temperature) to a septumcapped vial. The masses of each of the standard solutions were measured on a calibrated 

analytical balance.

2.1.2 Gas Chromatographic Method for Ethanol-Water Solutions

A gas chromatographic method was developed for determination of ethanol levels in oral fluids. 

A Hewlett-Packard (HP) 5890 Series II gas chromatograph equipped with an FID detector and 

attached to an HP model 3395 recording integrator was used. Manual injections of 1 μL were 

split 22:1 in the split injection port (4-mm, with cup and glass wool, split injection liner). 

Injector and detector temperatures were 200 °C. The column was a 15 m x 0.25 mm AT-WAX 

fused silica capillary column with a stationary phase thickness of 0.50 μm. The oven program 

was 35 °C for 2.0 min, ramp l of 15 °C/min to 80 °C, ramp 2 of 40 °C/min to 120 °C, hold at 

120 °C for 2.0 min. The total run time was 8.0 min. The helium carrier gas had a flow rate of 

1.6 mL/min through the column at a head pressure of 60 kPa and a total flow rate of 50 mL/min. 

2.1.3 Calculation of Peak Area Ratio, the Measure Directly Related to Analyte 

 Concentration

An internal standard approach was used for quantitation. To correct for variations in injection 

volume, calculations were based on relative response factors that employed 1-propanol as the 

internal standard. In practice, the peak area ratio for the analyte (ethanol) to the internal standard 

(1-propanol) is proportional to the mass ratio for the analyte to the internal standard. 

2.1.4 Linear Range

Ethanol standards of nominal concentrations 0.05 % to 7.5 % (mass fractions, corresponding to 

0 % to 2.0 % ethanol in the standard solutions) were tested by GC-FID. All of the calibration 

standard solutions were within the linear range of the method.

2.1.5 Detection Limit

To determine the detection limit of ethanol, two dilute solutions were prepared so as to give 

signal to noise (S/N) ratios between 4-10 and 50-100. Six injections of each dilute solution were 

made, and the average peak area ratio served as the signal, and the standard deviation served as 

the value for noise. This data was fit to a line, and the ethanol concentration corresponding to 

S/N = 3 was calculated as the detection limit. The 0.02 % (mass fraction) ethanol standard gave 

the higher S/N ratio of 57 and a 5.4-fold dilution of this standard produced the lower value with a 

S/N of 7. The detection limit of ethanol was determined to be 0.001 % (mass fraction).
3

2.1.6 Repeatability Study

Four ethanol standard solutions of nominal concentrations 0.020 %, 0.080 %, 0.20 %, and 

0.50 % (mass fractions) plus a blank (water) were prepared. Each standard plus blank was tested 

three times (three injections) on three consecutive days, and the peak area ratios were recorded. 

For all ethanol levels, the within-day variation of the peak area ratios was no different from the 

between-day variation as determined by ANOVA. The precision (relative standard deviation) 

for the combined (within- and between-day) data was on average 0.9 % for the three higher 

ethanol concentrations. The relative standard deviation increased quite a bit, to 12 %, for the 

lowest concentration (0.020 %).

The sensitivity, specificity, efficiency, positive predicative value and negative value were

determined for each set of data. Each parameter is defined as follows:

(TP FN)

TP ST

Eq 1

(TN FP)

TN SP

Eq 2

(TotalTests)

TP TN EF

Eq 3

(TP FP)

TP PPV

Eq 4

(TN FP)

TN NPV

Eq 5

ST = Sensitivity

TP = True Positive

FN = False Negative

TN = True Negatives

FP = False Positives

SP = Specificity

EF = Efficiency

PPV = Positive Predicative Value

NPV = Negative Predicative Value

2.1.7 Recovery Study

Experiments were performed to determine the accuracy of the method in measuring ethanol 

added to a known ethanol standard prepared in water. A 0.10 % (mass fraction) ethanol solution 
4

was prepared in a 100-mL volumetric flask. A 0.50-mL aliquot was taken and combined with 1-

propanol internal standard solution for GC-FID analysis. To the remaining ethanol solution was 

added 50 mg of pure ethanol to increase the concentration to about 0.15 % (mass fraction). A 

0.50-mL aliquot of this spiked ethanol solution was taken and combined with 1-propanol internal 

standard solution for GC-FID analysis. The test solutions were injected twice each on two 

consecutive days. The resultant blank-corrected area ratios were averaged and used to calculate 

the ethanol concentrations by comparison to the calibration line generated on the final day of the 

repeatability study. The calibration line was computed by unweighted linear regression.

The amount of ethanol in the original solution was subtracted from the measured amount of 

ethanol in the spiked solution to give the amount of ethanol added. The measured amount was 

divided by the gravimetric amount of ethanol added to determine the fractional recovery. The 

fractional recovery was 1.016 ± 0.055 (mean ± 1 SD).

2.1.8 Quantitative Study

The accuracy of the GC-FID method was assessed by determining the concentration of ethanol in 

two levels of Standard Reference Material (SRM) 1828b Ethanol-Water Solutions (BloodAlcohol Testing: Six Levels). One ampoule of each level of SRM was opened, and the liquid 

was immediately transferred to a septum-capped vial. The liquid was removed with a syringe for 

testing. Four ethanol calibration solutions of nominal concentrations 0.020 %, 0.080 %, 0.20 %, 

and 0.50 % (mass fractions) plus a blank (water) were prepared. Each sample, calibrant, and 

blank was tested twice on each of two consecutive days.

Calibration measurements provided an excellent fit using an unweighted linear regression model. 

The measured concentration of ethanol in the Level 1 sample (mean ± 1 SD) was 0.0188 ± 

0.0020 g ethanol per 100 g solution as compared to the certified value of 0.0195 ± 0.0002. The 

certified value was within the 95 % confidence interval (df = 6) of the measured value. The 

measured concentration of ethanol in the Level 3 sample (mean ± 1 SD) was 0.2904 ± 0.0019 g 

ethanol per 100 g solution as compared to a certified value of 0.298 ± 0.003 (95 % confidence 

interval). The certified value was outside the 95 % confidence interval for the measured value. 

The percent error for Level 3 was -2.5 %. The sensitivity, specificity, efficiency, positive 

predicative value and negative value were determined for each set of data. 

2.2 Experimental Procedures for Oral Fluid

2.2.1 Collection and Preparation of Oral Fluid

Since oral fluid was the medium used with the various drug detection devices under evaluation, 

the GC-FID method previously developed for use with ethanol water mixtures was verified for 

oral fluid. Oral fluid was obtained by expectoration from healthy volunteers. Nothing was 

introduced into the mouths of volunteers for at least 1 h prior to oral fluid collection. The 

collected oral fluid was pooled and frozen within 1 h of collection. The combined pool was 

generated over a 5-d period. The oral fluid was thawed and refrozen twice to reduce foaming 

and then was centrifuged for 30 min in a clinical centrifuge to remove suspended solids. The 

supernatant was separated and centrifuged for another 20 min. The resulting final supernatant 
5

was stored in a sealed container at 4 °C and served as the source of oral fluid in all subsequent 

studies.

2.2.2 Preparation of Standard Solutions, Spiked Oral Fluid, and Test Solutions

Ethanol standards used to spike the oral fluid were prepared in distilled water as described in

Section 2.1.1 at concentrations ranging from 0.1 % to 10 % (mass fractions).

Spiked oral fluid solutions were prepared by pipetting 0.5 mL of oral fluid to a vial with a 

septum lined cap, and adding 50 μL of the ethanol standard in water (transferred through the 

septum with a syringe). The masses of each liquid were measured on a calibrated analytical 

balance.

Test solutions were prepared by adding 0.5 mL of 1-propanol internal standard solution to the 

spiked oral fluid. The internal standard solution was transferred to the vial through the septum 

with a syringe, and its mass determined.

2.2.3 Gas Chromatographic Method for Oral Fluid

The method detailed in 2.1.2 was modified for the analysis of oral fluids. The GC program was 

amended to include an additional temperature ramp to ensure that no substances from the oral 

fluid were retained on the column. The third ramp was set at 25 °C/min until 220 °C and held 

for 4.00 min, for a total run time of 16.00 min. 

No significant differences were observed in chromatograms of oral fluids or water based 

samples, in the time range of interest. The retention times for ethanol and 1-propanol were 

unaffected, and the baseline remained stable. Small peaks from undetermined compounds were 

detected at 8.1 min and 12.9 min. 

2.2.4 Linear Range

Ethanol standards in oral fluid were tested using the GC-FID method described. Spiked oral 

fluid with nominal ethanol concentrations 0.04 % to 10 % (mass fraction) was tested. The linear 

range for ethanol in spiked oral fluid was 0 % to 2.0 % (mass fraction).

2.2.5 Detection Limit

The detection limit was determined by preparing a dilute solution of ethanol in oral fluid that 

gave a S/N ≈ 3. Six injections of the spiked oral fluid solution were made with the average peak 

area ratio serving as the signal and the standard deviation serving as the value for noise. An 

ethanol concentration of 0.002 % (mass fraction) in spiked oral fluid gave a S/N ratio of 2.9, 

close to a S/N ratio of 3 that was designated as the detection limit.
6

2.2.6 Repeatability Study

Four ethanol standards of nominal concentrations 0.04 %, 0.16 %, 0.40 % and 1.0 % (mass 

fractions) in spiked oral fluid plus a blank containing only oral fluid were prepared. Each sample 

was injected three times on three consecutive days and peak area ratios were recorded. The 

blank showed no peak at the ethanol retention time. For all ethanol levels, the within-day 

variation of the peak area ratios was no different from the between-day variation as determined 

by ANOVA. The precision (relative standard deviation) for the combined (within- and betweenday) data was on average was less than 2.5 % for all ethanol concentrations, with the largest 

uncertainty at each end of the concentration range.

2.2.7 Quantitative Study

Five ethanol standards of spiked oral fluid concentrations (nominal) 0.01 %, 0.02 %, 0.08 %, 

0.20 % and 0.50 % (mass fractions) were prepared. Each standard plus a blank (oral fluid) was 

tested twice on two consecutive days. Standard solutions were identical on the two days, but 

fresh spiked oral fluid and test solutions were prepared each day. Data analysis of these 

solutions gave a linear plot with a correlation coefficient of 0.9995 each day (see table 2).

2.2.8 Robustness

Test solutions were prepared with slightly different amounts of oral fluid (0.4 mL - 0.6 mL) to 

determine if the amount of oral fluid influenced the results. No significant differences in the 

detector response (peak area ratio) per amount of ethanol injected were found. Both low (0.02 %

mass fraction) and high (0.20 % mass fraction) nominal ethanol concentrations in spiked oral 

fluid were tested.

A test solution was left at room temperature for 3 d and then reanalyzed to check whether 

possible enzyme action and/or bacterial growth over that time frame affected the results. The 

0.02 % (mass fraction) ethanol test solution showed no significant difference in the GC-FID peak 

area ratios over the 3 day period.

2.2.9 Recovery Study

Experiments were performed to determine the accuracy of the method in measuring ethanol 

added to oral fluid. A 0.5-mL aliquot of spiked oral fluid (0.02 % mass fraction ethanol) was 

mixed with 0.5 mL 1-propanol internal standard solution and analyzed by GC-FID with duplicate 

injections. A known amount of 0.8 % (mass fraction) aqueous ethanol standard was added to the 

remaining test solution, thereby increasing the ethanol concentration in the spiked oral fluid to 

about 0.10 % (mass fraction). The spiked test solution was injected in duplicate. The peak area 

ratios were averaged and used to calculate measured ethanol concentrations by unweighted linear 

regression.

The amount of ethanol in the original solution was subtracted from the measured amount of 

ethanol in the spiked solution to obtain the amount of ethanol added. The measured amount of 
7

ethanol was divided by the gravimetric amount of ethanol added to determine the fractional 

recovery. The recovery was 0.931 ± 0.040 (mean ± 1 SD).

The recovery study was repeated in the same manner as above but with a smaller addition of 

ethanol, this time using a 0.2 % (mass fraction) ethanol standard. Thus, the ethanol 

concentration changed from 0.02 % to 0.04 % (mass fraction). The measured recovery was 

1.03 ± 0.19 (mean ± 1 SD). The uncertainty was increased due to the larger relative uncertainty 

associated with smaller quantities of added ethanol. 

2.3 Evaluation of Device Sensitivity for the Determination of Ethanol in Oral Fluid 

2.3.1 Preparation of Solutions for Device Testing

Five standard solutions of spiked oral fluid, with nominal ethanol concentrations of 0.01 %, 

0.02 %, 0.03 %, 0.08 % and 0.12 % (g ethanol / 100 g spiked oral fluid) were prepared by mixing 

15 mL of oral fluid (exact mass known) with 1.5 mL of the appropriate aqueous ethanol standard 

(exact mass known). 

Ethanol standards used to spike the oral fluid were prepared in high purity water as described in 

section 2.1.1 at nominal concentrations: 0.1 %, 0.2 %, 0.3 %, 0.8 % and 1.2 % (g ethanol / 100 g 

aqueous standard). 

For each of the testing devices, a 0.5-mL aliquot of spiked oral fluid was pipetted to a 10-mL 

beaker. To prepare a test solution for GC-FID, a 0.5-mL aliquot of spiked oral fluid was 

transferred with a syringe to a septum-capped vial and weighed. Then, a 0.5 mL aliquot of 1-

propanol internal standard solution (0.10 g/100 mL in water) was added with a syringe to the 

same vial and weighed. Fresh aliquots of spiked oral fluid and test solutions were prepared each 

time a device was tested.

The test devices refer to percent ethanol concentrations that generally are interpreted as the 

equivalent blood alcohol level in units of g ethanol / 100 mL of blood. The units used in this 

report are g ethanol / 100 g fluid and no correction factor for equivalent blood alcohol levels has 

been applied. The ratio of oral fluid ethanol concentration to blood ethanol concentration for 

samples obtained simultaneously has been found to be approximately 1.08 (Gubala, et al. Pol. J. 

Pharmacol. 2002, 54, 161-165), so the oral fluid concentration is a very good indicator of blood 

alcohol concentration (BAC).

2.3.2 Procedure for Testing the Devices

Each of the five devices was tested with spiked oral fluid at each of the five ethanol 

concentrations (described above) plus a blank (oral fluid without added aqueous ethanol). Five 

trials at each of the concentrations were performed for each device, and a test solution that was 

injected into the GC-FID accompanied each test. The QED A150 testing swab was placed in the 

oral fluid for 45 s as specified by the manufacturer. All the other devices were placed in the oral 

fluid for 15 s to saturate the test pad; saturation with oral fluid was specified by the 

manufacturers. For specific details and testing procedures of each device, see below.
8

 Device Manufacturer Response Category

 QED A150 Orasure Quantitative 

Technologies

 Alco-Screen Chematics Semi-Quantitative 

 Alco-Screen 02 Chematics Qualitative 

 Rapid Response Biotechnostix Qualitative 

 OnSite Varian Qualitative 

QED A150

The QED Al50 Saliva Alcohol Test manufactured by Orasure Technologies, Inc., is designed to 

provide a quantitative determination of blood alcohol concentration (BAC) in 2 min from a fresh 

oral fluid sample. The QED A150 is capable of determining alcohol levels in the range of 

0.01 % to 0.145 % (g ethanol / 100 mL of blood, [units assumed]) with a reading precision of 

0.005 %. The device works by an enzymatic method. Alcohol dehydrogenase catalyzes the 

oxidation of alcohol to acetaldehyde and reduces NAD to NADH at the same time. An alkaline 

pH and acetaldehyde trapping agent are employed to ensure that the reaction generates one mole 

of NADH for each mole of ethanol in the sample. Diaphorase, an unspecified oxidizing agent, 

and a tetrazolium salt are all incorporated into a solid reagent, which reacts with the NADH to 

form a colored product (formazan dye).

The QED Al50 test package was opened immediately prior to use. The instructions for use state 

that devices are to be discarded if the QA Spot (a quality control indicator at the top of the 

device's scale) is purple or the desiccant package is pink; however, none of the packages had to 

be discarded. The instructions for use specify that the swab should be actively rubbed around the 

mouth and under the tongue for 30 s to 60 s or until the swab was saturated. To replicate these 

conditions, a swab was placed in the 0.5-mL aliquot of spiked oral fluid and rubbed around for 

45 s. The QED Al50 was then placed on a flat surface and the applicator inserted into the port 

with gentle, steady pressure. At this point, a capillary tube was filled, and the oral fluid reached 

the QA Spot. The background appeared pink when the capillary was filled. The test was 

completed in 2 min and the device was not moved during this time. After 2 min a purple bar 

along a printed scale showed the ethanol concentration. The QA Spot also turned purple by this 

time. Manufacturer instructions state that if the QA Spot was not purple within 5 min from the 

start of the test, the test is invalid. No tests were invalidated by this criterion.

The manufacturer specified that the test should be administered at least 10 min after eating or 

drinking and should be performed at an ambient temperature within the range 15 °C to 30 °C. 

The following compounds are specified not to interfere with the test's operation: ethylene glycol, 

acetone, methanol, 1-butanol, 2-butanol, 1-propanol, 2-propanol, 1-pentanol, ascorbic acid. 

However, use of alcohol-containing products, such as mouthwash, cough syrup, breath spray, or 

chewing tobacco were said to cause elevated results in some cases.
9

Alco-Screen

The Alco-Screen test is made by Chematics, Inc., and is intended for the semi-quantitative 

determination of ethanol concentration in oral fluid. The device, consisting of a plastic test strip 

with a reactive pad at one end, is designed to detect BAC in the range of 0.02 % to above 0.30 % 

(g ethanol / 100 mL of blood, [units assumed]) ethanol with a reading precision ranging from 

0.01 % to 0.1 % depending on the amount of ethanol present. The precision is greater at lower 

concentrations of ethanol according to the color gradient chart provided with each test. A 

reactive pad turns gray-green to gray-blue depending on the amount of alcohol present. The 

ethanol concentration is determined by comparison with a calibrated color chart that is provided. 

Alco-Screen uses an alcohol oxidase enzyme to oxidize ethanol to acetaldehyde with the 

accompanied production of hydrogen peroxide, which then reacts with a hydrogen donor 

(tetramethylbenzidine) to produce a colored product and water. According to the manufacturer, 

the device responds to methyl, ethyl, and allyl alcohols, but not alcohols with more than 5 

carbons or glycine, glycerol, and serine.

The Alco-Screen package was opened just before use and discarded if the test strip was 

discolored in any way. None of the strips tested were discolored. The reactive pad was saturated 

with oral fluid for 15 s and a timer started. The color of the reactive pad was observed at 2 min 

and the results interpreted. The manufacturer warned results might be erroneous after 2 min 

30 s. The test was designed to be performed at least 15 min after introducing anything into the 

mouth and at temperatures less than 80 °F (27 °C) to prevent degradation of the reaction pad. 

Peroxides and strong oxidizers may enhance color development, while reducing agents, bilirubin, 

L-dopa, L-methyldopa, and methampyrone may inhibit color development. The manufacturer 

also warned that the test was sensitive to alcohol vapors and should be performed in an area 

where these are not present.

Alco-Screen 02

The Alco-Screen 02 test is made by Chematics, Inc., and is intended for the qualitative 

determination of ethanol concentration in oral fluid. The device, consisting of a plastic test strip 

with a reactive pad at one end, gives a positive response for samples with a BAC of 0.02 % 

(g ethanol / 100 mL of blood, [units assumed]) or higher and a negative response in all other 

cases. A line on the reactive pad turns green in the presence of ethanol; no line appears at 

ethanol concentrations below 0.02 % (g ethanol / 100 mL of blood, [units assumed]). AlcoScreen 02 uses alcohol oxidase to oxidize ethanol to acetaldehyde with the accompanied 

production of hydrogen peroxide, which then reacts with a hydrogen donor 

(tetramethylbenzidine) to produce a colored product and water.

The Alco-Screen 02 package was opened just before use and discarded if the test strip was 

discolored in any way. None of the strips tested were discolored. The reactive pad was saturated 

with oral fluid for 15 s and a timer started. After 15 s the device was removed from the spiked 

oral fluid, and after 10 s more excess spiked oral fluid was shaken from the pad as specified by 

the manufacturer. The test was completed in 4 min and the distinct green bar indicated a positive 

result. According to the test maker, after 5 min the result might be erroneous.
10

The test is subject to many of the same interferences as Alco-Screen, including: peroxides, 

strong oxidizers, ascorbic acid, tannic acid, pyrogallol, mercaptans, tosylates, uric acid, bilirubin, 

L-dopa, L-methyldopa, methampyrone, and oxalic acid. However, these are not normally 

present in human oral fluid in large enough concentrations to be significant according to the 

manufacturer. Test subjects were not to introduce anything into their mouths for 15 min prior to 

the test. According to the manufacturer, the device performs best at room temperature and 

should not be stored above 80 °F (27 °C). Alco-Screen 02 may also be sensitive to alcohol

vapors in the air.

Rapid Response Alcohol Test

The Rapid Response Alcohol Test is made by Biotechnostix, Inc., and is intended to determine 

the presence of alcohol in a single step. The device, consisting of a plastic test strip with a 

reactive pad at one end, gives a positive response for samples with a BAC of 0.02 % (g ethanol / 

100 mL of blood, [units assumed]) or higher and a negative response in all other cases. No 

information on the chemical basis or specificity of the test was provided by the manufacturer.

The Alcohol Test package was opened just before use and discarded if the test strip was 

discolored in any way. None of the strips tested were discolored. The reactive pad was saturated 

with oral fluid for 15 s and a timer started. The result was interpreted after 2 min. A change in 

color of the reactive pad from light yellow to blue-green (as shown on the foil package) indicated 

a positive result. As with other devices of this kind, nothing was to be introduced into the 

mouths of test subjects for 15 min before the test and the device was to be stored between 4 °C to 

27 °C.

On Site

The On Site Alcohol testing device is made by Varian, Inc., and is intended for the qualitative 

determination of ethanol concentration in urine or saliva. The device is a small kit containing a 

reagent pipet, a urine specimen pipet, a foam pad for collecting oral fluid, and a reaction cassette. 

It employs a similar alcohol dehydrogenase method as the QED A150. A urine or oral fluid 

sample is placed onto a chemically treated pad that "volatilizes" reducing alcohols. These vapors 

are concentrated on a membrane containing an enzyme solution and a tetrazolium salt. When 

this enzyme-tetrazolium salt comes in contact with ethanol vapor, a formazan dye results, 

producing a purple + sign.

To administer the test, the foil was peeled back and one drop of reagent from a reagent well was 

transferred using the reagent pipet to a circle (reagent well) molded on the cassette labeled 

"results." Then the sample was applied to the sample well using the foam pad that had been 

saturated with spiked oral fluid for 15 s. The results were interpreted after 2 min.

According to the manufacturer, the On Site test should be performed at least 10 min after eating 

or drinking to avoid contamination of the oral cavity. The tests should also be performed in a 

temperature range of 18 °C to 29 °C and the kits stored between 15 °C and 30 °C. The 

manufacturer stated that the following substances produced no interference when tested at 
11

1.00 % (mass/volume fraction): acetaldehyde, acetone, 2-butanol, ethylene glycol, glycerol and 

methanol or at 0.10 % (mass/volume fraction): 1-butanol and isopropanol. 1-Propanol gave a 

faint positive at 0.05 %. Ingestion or general use of over-the-counter medications and products 

containing alcohol may give a positive result in some cases.

2.3.3 Sensitivity of the Devices: Quantitative Devices

QED A150

Since the QED A150 was designed to give a quantitative response, the testing results for this 

device were assessed by comparing the ethanol concentration obtained from the device with the 

ethanol concentration of the spiked oral fluid analyzed simultaneously with the GC-FID. The 

capillary filled easily with 0.5 mL spiked oral fluid and the QA spot provided an indicator that 

the test was valid. Bubbles in the capillary made it somewhat more difficult to read the test 

results at higher concentrations of ethanol. A graph was constructed with the device response 

plotted along the y-axis and the average ethanol concentration determined by GC-FID plotted on 

the x-axis (see fig. 1). The slope of this line was 1.06. This is consistent with the value 1.08 

reported for the ratio of ethanol oral fluid concentration relative to blood ethanol concentration, 

(Gubala et al., Pol. J. Pharmacol 2002, 54, 161-165).

QED A150 Testing Results

y = 1.0579x + 0.0009

R

2

 = 0.9976

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.00 0.02 0.04 0.06 0.08 0.10 0.12

% Ethanol (GC-FID)

% Ethanol (QED)

Figure 1. QED A150 Testing Results
12

Alco-Screen

Because the Alco-Screen device provided a color gradient designed to correspond to various 

blood alcohol levels, the results for this test were assessed by comparing the ethanol 

concentration obtained from the device with the ethanol concentration of the spiked oral fluid 

analyzed simultaneously by GC-FID (see fig. 2). The color chart provided with the device was 

used to estimate ethanol concentrations. The color of the test strip was matched with, or 

estimated between, the colors on the chart. The estimated concentrations from the device are 

plotted on the y-axis of figure 2. The Alco-Screen provided a nonlinear response (R

2

= 0.61), 

with consistently high responses to ethanol in oral fluid. For example, a concentration of about 

0.01 % (mass fraction) ethanol gave a color that indicated 0.08 % (mass fraction) ethanol 

according to the color chart provided. 

AlcoScreen Testing Results

0.00 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32

% Ethanol (GC-FID)

% Ethanol (AlcoScreen)

Figure 2. AlcoScreen Testing Results

2.3.4 Sensitivity of the Devices: Qualitative Devices

The response of each of the three qualitative ethanol-test devices was determined to be positive 

or negative. The response was then characterized as true or false as compared with the % 

ethanol concentration in spiked oral fluid from the GC-FID tests. Each of these four possible 

responses was then summed, determining the total number of true positive, false positive, true 

negative, and false negative responses (see table 1). 
13

Table 1. Summary of Results for Qualitative Devices

 Device # tests # T positives # F positives # T negatives # F negatives 

AlcoScreen02 30 20 0 10 0

Rapid Response 30 10 0 10 10

On Site 30 20 0 10 0

Alco-Screen 02

The Alco-Screen 02 response was compared with the % ethanol determined from the spiked oral 

fluid by GC-FID analysis. The device indicated no false positives or false negatives. The 

sensitivity, specificity, efficiency, positive predicative value and negative predicative value were 

all one. The green line that indicated a positive response was lighter at the 0.02 % (mass 

fraction) limit and increased in intensity as the amount of ethanol increased.

Rapid Response

The Rapid Response alcohol testing device did not provide positive indication of ethanol at 

concentrations of 0.02 % (mass fraction) or 0.03 % (mass fraction). These false negatives 

lowered the sensitivity and negative predicative value to 0.5, when compared with the percentage 

ethanol measured by GC-FID. The efficiency was 0.67, while specificity and positive 

predicative value were both 1.0. The positive test tended to show a faint green color with blue 

splotches instead of a fully colored testing pad.

On Site

The On Site device gave a negative response for all tests for the blank and at 0.01 % (mass 

fraction) ethanol concentration, and a positive response for the higher levels of ethanol. These 

results meant that the sensitivity, specificity, efficiency, positive predicative value and negative 

predicative value were all equal to one, when compared with the % ethanol determined by GCFID. The purple plus symbol was lighter and thinner with lower amounts of ethanol.

2.3.5 Evaluation of Devices with Other Sources of Oral Fluid

To produce the pool of oral fluid used in the studies described above, fresh oral fluid was 

collected, frozen and thawed twice, and finally centrifuged twice. The supernatant was removed 

and spiked with aqueous ethanol to produce the spiked oral fluid. In an alternative approach, the 

aqueous ethanol was added at the outset to pooled oral fluid to see the effect, if any, of 

processing on the concentration of ethanol. After the addition of ethanol to the oral fluid, the 

sample was processed as in section 2.2.1. This sample was compared with an oral fluid sample 

that was spiked with ethanol after processing. Solutions were analyzed in triplicate by GC-FID. 

The GC-FID results with the two types of oral fluid were not significantly different. The 

removal of solids, etc., did not seem to affect the determination of ethanol.

Additional tests were performed on the alcohol testing devices using unprocessed oral fluid 

(directly from the mouth or expectorated). In one test, the swab or the reactive pad was inserted 
14

directly into the mouth of a healthy volunteer and clean oral fluid was collected. Each device 

remained in the mouth for 15 s, except for the QED A150 swab, which remained for 45 s in 

accordance with manufacturer's instructions. Each device was moved around the cheeks and 

under the tongue. For the QED A150 it was more difficult to fill the capillary and more bubbles 

were present than with the pooled and processed oral fluid. No other differences in device 

performance were observed for the use of pooled and processed oral fluid.

Another test, recently expectorated oral fluid from a healthy volunteer was spiked to a 

concentration of 0.02 % (mass fraction) and 0.08 % (mass fraction) ethanol. The oral fluid was 

spiked with the appropriate amount of aqueous ethanol and used immediately for testing. Each 

of the devices was tested once at both concentrations with accompanying GC-FID analyses. The 

GC-FID results with unprocessed spiked oral fluid and with processed spiked oral fluid were not 

significantly different. All of the devices performed similarly with the two sources of oral fluid, 

except for the Alco-Screen 02, which gave a negative response to the 0.02 % (mass fraction)

nominal ethanol concentration.

2.4 Investigation of Interfering Substances

To test how selective each device was toward ethanol, the devices were tested in the presence of 

four substances that might commonly be found in oral fluid: acetaminophen, L-ascorbic acid, 

caffeine, and nicotine. While the literature was silent on the concentrations of these substances 

in oral fluid, common (maximum) levels in blood were available. These values were utilized to 

set interferent levels in oral fluids. The following concentrations were used in this study: 

acetaminophen, 25 mg/dL; L-ascorbic acid, 2 mg/dL; caffeine, 2 mg/dL; and nicotine, 3 mg/dL. 

Each interfering substance was added to aqueous ethanol solutions that were then used to spike 

clean oral fluid.

2.4.1 Preparation of Solutions for Device Testing

Solutions were prepared to contain 0.1 %, 0.3 % and 0.5 % ethanol (g ethanol/100 g aqueous 

standard) and interfering substances at levels 10 times the concentrations listed above (12 

solutions). After thorough mixing, 15 mL each solution was transferred to a septum-capped vial 

and stored at 4 °C. 

Spiked oral fluid was prepared at nominal ethanol concentrations of 0.01 %, 0.03 %, and 0.05 % 

(mass fractions) by adding 50 μL of each of these solutions to 0.50 mL aliquots of oral fluid. 

The resulting 0.55-mL sample was applied directly to the testing device.

Solutions for analysis by GC-FID were prepared as in section 2.2.2. Fresh aliquots of spiked 

oral fluid and test solutions were prepared each time a device was tested.

2.4.2 Procedure for Testing the Devices

Each of the five devices was tested in triplicate with spiked oral fluid at each of three ethanol 

concentrations with each interference (described above). A GC-FID analysis accompanied each 

test. The QED A150 testing swab was placed in the oral fluid for 45 s as specified by the 
15

manufacturer. All the other devices were placed in the oral fluid for 15 s to saturate the test pad; 

saturation with oral fluid was specified by the manufacturers.

2.4.3 Interference Testing Results

Quantitative and Semi-Quantitative Devices

QED A150

Since the QED Al50 was designed to give a quantitative response, the testing results for this 

device were assessed by comparing the ethanol concentration obtained from the device with the 

ethanol concentration of the spiked oral fluid determined simultaneously by GC-FID. A graph 

was constructed with the device response plotted along the y-axis and the ethanol concentration 

from GC-FID plotted along the x-axis (see fig. 3). Lines were constructed for the results with 

each potential interfering substance added, and for the results without added interference (open 

squares). Similar results were obtained in the presence and in the absence of the potential 

interfering substances. A linear relationship between device response and ethanol concentration 

from GC-FID was apparent in all cases; the R

2

values were 0.99, 0.99, 1.00, and 0.99 for 

acetaminophen, L-ascorbic acid, caffeine, and nicotine respectively. 

QED A150 Interference Testing Results

0

0.02

0.04

0.06

0.08

0 0.02 0.04 0.06 0.08

% Ethanol (GC-FID)

% Ethanol (QED)

Figure 3. QED A150 Interference Testing Results
16

Alco-Screen

Because the Alco-Screen device provided a color gradient designed to correspond to various 

blood alcohol level, the results for this test kit were assessed by comparing the ethanol 

concentration obtained from the device with the ethanol concentration of spiked oral fluid 

analyzed simultaneously by GC-FID. The color chart provided with the device was used to 

estimate ethanol concentrations. Results for tests carried out in the presence of potential 

interferences are shown in figure 4. The device response over a narrow concentration range was 

more linear than the results of section 2.3.3, with R

2

values of 0.87, 0.97, 0.94, and 0.97 for 

acetaminophen, L-ascorbic acid, caffeine, and nicotine respectively.

AlcoScreen Interference Testing Results

0 0.08 0.16 0.24 0.32

% Ethanol (GC-FID)

% Ethanol (AlcoScreen)

Figure 4. Alco-Screen Interference Testing Results

Qualitative Devices

The response of each of the three qualitative ethanol-test devices was determined to be positive 

or negative (over or under 0.02 % mass fraction ethanol). The response was then characterized 

as true or false as compared with the % ethanol in spiked oral fluid from the GC-FID tests. Each 

of the four possible responses was then summed, determining the total number of true positive, 

false positive, true negative, and false negative responses (see table 2).
17

Table 2. Summary of Results for Qualitative Devices with Potential Interferences

 Device # tests # T positives # F positives # T negatives # F negatives 

AlcoScreen02 36 24 0 12 0

Rapid Response 36 23 0 12 1

On Site 36 24 0 12 0

Alco-Screen 02

The Alco-Screen 02 performance was unaffected by the presence of common, potentially 

interfering substances. The devices showed no false positives or negatives when tested with any 

of the interfering substances. As such, the sensitivity, specificity, efficiency, positive predicative 

value, and negative predicative value were all one.

Rapid Response

The Rapid Response test performance was slightly affected by the presence of interfering 

substances. The detection of ethanol at 0.03 % (mass fraction) was achieved in these tests, 

contrary to results with unadulterated oral fluid. The Rapid Response device gave a single false 

negative at 0.03 % (mass fraction) ethanol in the presence of caffeine, and this reduced the 

sensitivity of the device with caffeine to 0.83, the efficiency to 0.89 and the negative predicative 

value to 0.75. The values for all other parameters with added caffeine and with the other added 

substances were one.

On Site

The On Site device appeared to be unaffected by the addition of the four potential interferences. 

The test provided no false positive or false negative values. This behavior was the same as

observed for the On Site device without added substances. The sensitivity, specificity, 

efficiency, positive predicative value, and negative predicative value were all one for this device.

The selectivity of all of the devices was quite good. None of the potential interferents -

acetaminophen, L-ascorbic acid, caffeine, nicotine - at high normal levels caused problems with 

the tests. 

3. DEVICES FOR TESTING FOR DRUGS OF ABUSE

3.1 Experimental

3.1.1 Description of Devices Tested

The point-of-collection drug-testing devices, sources, and catalog and lot numbers are shown in 

table 3.
18

Table 3. Point-of-Collection Drug-Testing Devices to be Analyzed

Point-of-Collection 

Drug-Testing Device

Company Address Catalog 

Number

Lot Number

Oral Fluid Drug 

Screen Device

Medimpex United 

Inc.

984 Bristol Pike

Bensalem, PA 

19020

DOA 5050079 L030200-01

ORAL SCREEN 

Saliva 4

Craig Medical 

Distribution Inc.

1185 Park Center 

Drive, Building P

Vista, CA 

92081-8305 

B52008 032406

iScreen Oral Fluid 

Device 6

RDI Rapid Detect 

Inc.

2809 N. 

Broadway, Suite 7

Poteau, OK 74953

i)DOA5100336

ii)DOA6030435 Lo020241-01

Oratect II Branan Medical 

Corporation

10015 Muirlands 

Road, Suite C

Irvine, CA 92618

HM11 G0038

The saliva used in the following analysis was normal human pooled saliva, obtained from 

Biochemed Services, Winchester, VA 22601 (shown in table 4). The saliva was filtered through 

a large Buchner funnel into a 500 mL Erlenmeyer flask under vacuum. The saliva was filtered 

through Whatmann® 541, Hardened Ashless Circles 110 mm filter paper.

Table 4. Pooled Human Saliva

Saliva Batch Volume Lot Number

1 1 x 250 mL BC020106

2 2 x 250 mL BC031406

3 1 x 250 mL BC040506

4 1 x 250 mL BC061406

3.1.2 Sample Preparation

Stock solutions were prepared by dissolving ≈1 mg quantities of each analyte (exact mass 

known) in 100 mL solvent in a volumetric flask. Acetonitrile was used for solutions of cocaine, 

and methanol was used in preparation of solutions for all other drugs. These 10 μg/mL solutions 

were then diluted 1 to 10 to give solutions at 1 μg/mL. Solutions containing isotopically labeled 

reagents were prepared by a 1:100 dilution of commercially available solutions at a concentration level ≈100 μg/mL. The target analyte, manufacturer and lot number for each drug is 

shown in tables 5 and 6.
19

Table 5. Standard Stock Solutions for Target Analytes

Target Analyte Drug Lot

Number

Manufacturer

Cocaine Cocaine Hydrochloride E232019

Mallinckrodt Corporation

675 McDonnell Blvd. 

Hazelwood, MO 63042

Phencyclidine Phencyclidine 

Hydrochloride 40H050

Sigma-Aldrich, Inc.

3050 Spruce Street

St. Louis, MO 63103

Codeine Codeine Sulfate E277086

Mallinckrodt Corporate

675 McDonnell Blvd. 

Hazelwood, MO 63042

Morphine Morphine Free Base E294032

Mallinckrodt Corporate

675 McDonnell Blvd. 

Hazelwood, MO 63042

Amphetamine Amphetamine Sulfate 30H0296

Sigma-Aldrich, Inc.

3050 Spruce Street

St. Louis, MO 63103

Methamphetamine Methamphetamine 

Hydrochloride 30H0291

Sigma-Aldrich, Inc.

3050 Spruce Street

St. Louis, MO 63103

(±)-11-nor-9-carboxy-∆

9

-

tetrahydrocannabinol

Tetrahydrocannabinol 

Carboxylic Acid

31533-

70B

Cerilliant TM

14050 Summit Drive #121 

Austin, Texas 78728
20

Table 6. Isotopically Labeled Internal Standards for Target Analytes

Target Analyte Drug Lot 

Number

Manufacturer

Cocaine Cocaine – D3 30896-13G

Cerilliant TM

14050 Summit Drive #121 

Austin, Texas 78728

PCP Phen-D5-cyclidine HCl 5424-M

MSD Isotopes

Division of Merck Forest 

Canada Inc., Montreal, 

Canada

Codeine Codeine – D3 H2O 1747-P

MSD Isotopes

Division of Merck Forest 

Canada Inc., Montreal, 

Canada

Morphine Morphine-D3 hydrochloride 123H5951

Sigma Chemical Company

P.O. Box 14508, St. Louis, 

MO 63178 

Amphetamine (±)-Amphetamine-D5 34260-03A

Cerilliant TM

14050 Summit Drive #121 

Austin, Texas 78728

Methamphetamine (±)-Methamphetamine-D5 33387-39B

Cerilliant TM

14050 Summit Drive #121 

Austin, Texas 78728

(±)-11-nor-9-carboxy-∆

9

-

tetrahydrocannabinol

Tetrahydrocannabinol-D3

Carboxylic Acid 6341-39

Research Triangle Institute

Research Triangle Park,

NC 27709-2194

Four sets of saliva samples were prepared for the analysis of the seven target analytes (tables 7-

10). Each set of samples consisted of small aliquots of saliva, pipetted into plastic centrifuge 

tubes and spiked with both the standard solutions and the isotopically labeled internal standard to 

give approximately 1:1 ratio of analyte to internal standard. Each set of saliva samples contained 

a range of concentrations to allow LOD for the target analyte to be determined within that 

particular set.
21

Table 7. Set 1 – PCP & Cocaine

Concentration 

(ng/mL)

Vol. of 

Saliva 

(mL)

Vol. of PCP 

stock solution 

(μL)

Vol. of Cocaine 

stock solution 

(μL)

Vol. of PCPD5 (μL)Vol. of 

Cocaine-D3

(μL)

50 5 250 250 250 250

40 5 200 200 200 200

30 6.7 201 201 201 201

25 8 200 200 200 200

20 8 160 160 160 160

15 8 120 120 120 120

10 8 80 80 80 80

5 8 40 40 40 40

Table 8. Set 2 – Codeine & Morphine

Concentration 

(ng/mL)

Vol. of 

Saliva 

(mL)

Vol. of 

Codeine 

stock solution 

(μL)

Vol. of Morphine 

stock solution 

(μL)

Vol. of 

Codeine-D3

(μL)

Vol. of 

Morhpine-D3

(μL)

60 5 300 300 300 300

50 5 250 250 250 250

45 5 225 225 225 225

40 5 200 200 200 200

35 5 175 175 175 175

30 5 150 150 150 150

25 8 160 160 160 160

10 8 80 80 80 80

5 8 40 40 40 40

Table 9. Set 3 – Amphetamine (Amph.) & Methamphetamine (M.Amph.)

Concentration 

(ng/mL)

Vol. of 

Saliva (mL)

Vol. of Amph. 

stock solution 

(μL)

Vol. of 

M.Amph. stock 

solution (μL)

Vol. of 

Amph-D5

(μL)

Vol. of M.Amph-D5

(μL)

50 5 250 250 250 250

40 5 200 200 200 200

30 6.7 201 201 201 201

25 8 200 200 200 200

20 8 160 160 160 160

15 8 120 120 120 120

10 8 80 80 80 80

5 8 40 40 40 40
22

Table 10. Set 4 – Carboxy-THC

Concentration 

(ng/mL)

Vol. of Saliva 

(mL)

Vol. of Carboxy-THC stock 

solution (μL)

Vol. of Carboxy-THCD3 (μL)

60 5 300 300

50 5 250 250

40 5 200 200

30 5 150 150

20 8 160 160

12 8 96 96

6 8 48 48

A set of calibrants was made for each set of saliva samples. This enabled the concentration of the 

target analyte in each solution to be determined by GC/MS (see table 11).

Table 11. Standard Solutions

Ratio of (Unlabelled : Labeled) 

Standards

Vol. of Unlabelled Solution 

(μL)

Vol. of Labeled Solution 

(μL)

1.2:1 480 400

1.1:1 440 400

1.0:1 400 400

0.9:1 360 400

0.8:1 320 400

Solutions were made up for 5 orally administered over the-counter drugs and caffeine. One dose 

was dissolved in deionized (DI) water and a subsequent aliquot diluted with saliva to give a 

solution at 0.1 mg/mL. The caffeine solution was made up by dissolving 1 mg of caffeine in 

10 mL of saliva. table 12 below shows how the solutions were prepared.

Table 12. Over the Counter Drugs

Solution A Solution B

Target Analyte Brand 

Name

Quantity 

in one dose

Vol. of 

Water

Vol. of 

Solution A

Vol. of 

Saliva (mL)

Concentration 

(mg/mL)

Acetaminophen Tylenol 500 mg 100 mL 0.2 10 0.1

Ibuprofen Advil 200 mg

100 mL

(plus 100 

mL Ethyl 

Alcohol 

200% 

proof)

1.0 10 0.1

Aspirin Aspirin 325 mg 100 mL 0.31 10 0.1

Naproxen 

Sodium Aleve 220 mg 100 mL 0.45 10 0.1

Pseudoephedrine

Triaminic 

Cold & Flu 

Syrup

15 mg 10 mL 0.67 10 0.1

Caffeine N/A N/A N/A 10 0.1
23

Solid Phase Extraction

Prior to the solid phase extraction (SPE) of the target analytes from the saliva samples, each SPE 

method was verified using a solution of the target analyte and water. Two duplicate samples 

were made up at a concentration of 100 ng/mL. Sample 1 had the internal standard added prior 

to the extraction taking place. Sample 2 had the internal standard added after the extraction had 

taken place and prior to drying down by evaporation. The recovery is expressed as a % and was 

calculated from the measured unlabeled: labeled ratios of sample 1 (S1) and sample 2 (S2) using 

the following formula:

% Recovery = (S2/S1) x 100 Eq 6

Solid Phase Extraction of Set 1 (PCP/Cocaine)

Both PCP and cocaine were extracted from the saliva samples in Set 1. 130 mg Bond Elut 

Certify cartridges (Varian, Inc., Walnut Creek, CA) were used which isolated compounds of 

interest by non-polar and cation exchange mechanisms. Each saliva aliquot was adjusted to pH 

6.0 (±0.5) by adding 2 mL of phosphate buffer (pH 6.0), and then 100 μL of 1M hydrochloric 

acid. The column was conditioned with 2 mL methanol and 2 mL 100 mM phosphate buffer 

(pH 6.0). The sample was loaded onto the cartridge at a rate of 2 mL/min. The loaded cartridge 

was then washed with 6 mL DI water, and 3 mL 1M acetic acid. The cartridge was then dried by 

aspiration for 5 min (at 15 KPa) and washed with 6 mL methanol. The PCP and cocaine were 

eluted from the cartridge with 2 mL methylene chloride/isopropanol/ammonium hydroxide 

(78/20/2). The eluents were evaporated to dryness with nitrogen at approximately 35 oC and the 

analyte was then dissolved in N,O-bis(trimethylsilyl)acetamide (BSA) for GC/MS measurement. 

The cocaine and PCP are not derivatized by the BSA, but its use as a solvent gives better 

chromatographic results.

Solid Phase Extraction of Set 2 (Codeine/Morphine)

Both codeine and morphine were extracted from the saliva samples in Set 2. 130 mg Bond Elut 

Certify cartridges were used to isolate compounds of interest by basic drug extraction with cation 

exchange and nonpolar mechanisms. Each saliva aliquot was adjusted to pH 8.0 - 8.5 by adding 

2 mL of phosphate buffer (pH 8.0). The column was conditioned with 2 mL methanol and 2 mL 

100 mM phosphate buffer (pH 8.0). The sample was loaded onto the cartridge at a rate of 2 mL/ 

min. Then the loaded cartridge was washed with 2 mL DI water, and 2 mL 100 mM acetate 

buffer (pH 4.0), 2 mL methanol and dried by aspiration for 2 min (at 10 KPa). The codeine and 

morphine were eluted from the cartridge with 2 mL methanol/ammonium hydroxide (98/2). The 

eluents were evaporated to dryness with nitrogen at approximately 40 oC and the analyte was 

then derivatized with bis(trimethylsilyl)trifluoroacetamide, 99 % with 1 % trimethylchlorosilane 

(BSTFA with 1 % TMCS).
24

Solid Phase Extraction of Set 3 (Amphetamine/Methamphetamine)

Both amphetamine and methamphetamine were extracted from the saliva samples in Set 3. 

130 mg Bond Elut Certify cartridges were used to isolate compounds of interest by basic drug 

extraction with cation exchange and nonpolar mechanisms. Each aliquot was adjusted to pH 6.0 

(± 0.5) by adding 2 mL of phosphate buffer (pH 6.0). The column was conditioned with 2 mL 

methanol and 2 mL 0.1 M phosphate buffer (pH 6.0). The sample was loaded onto the cartridge 

at a rate of 2 mL/min. Then the loaded cartridge was washed with 1 mL 1.0M acetic acid and 

dried by aspiration for 5 min (at 15 KPa). The cartridge was then washed with 6 mL methanol 

and dried aspiration for 2 min (at 10 PKa). The amphetamine and methamphetamine were eluted 

from the cartridge with 2 mL methylene chloride/isopropanol/ammonium hydroxide (78/20/2). 

The eluents were evaporated to dryness with nitrogen at approximately 35 oC and the analyte 

was then derivatized with heptafluorobutyric acid anhydride (HFAA).

Solid Phase Extraction of Set 4 (Carboxy-THC)

Carboxy-THC was extracted from the saliva samples in Set 4. 130 mg Bond Elut Certify 

cartridges were used to isolate the compound of interest by hydrophobic interactions; 

interferences were removed by ion exchange and secondary polar interactions. Each saliva 

aliquot was adjusted to pH 4.0 by adding 5 mL of 100 mM acetate buffer (pH 4.0). The column 

was conditioned with 2 mL methanol and 2 mL 50 mM phosphoric acid. The sample was loaded 

onto the cartridge at a rate of 2 mL/min. Then the loaded cartridge was washed with 9 mL 

50 mM phosphoric acid, 3 mL 50 mM phosphoric acid/methanol (80/20) and then dried by 

aspiration for10 min (at 15 KPa). The cartridge was then washed with 200 μL hexane. The 

carboxy-THC was eluted from the cartridge with 1 mL hexane/ethyl acetate (80/20). The eluents 

were evaporated to dryness with nitrogen at approximately 40 oC and the analyte was then 

derivatized with BSTFA with 1 % TMCS.

3.1.3 GC/MS Analysis

The following conditions were set for all the analyses carried out by GC/MS. The GC injector 

was heated to 270 oC and transfer line to 280 oC. Helium was used as the carrier gas with a head 

pressure of 15 psi. Samples were introduced by splitless injection, with the split valve opened at 

0.75 min. The mass spectrometer was operated in the electron ionization mode with ionization 

energy of 70 eV. The samples were introduced with an autosampler through an HP5890 series II 

gas chromatograph. Table 13 shows the temperature parameters and the target ions for each 

analyte.
Table 13. GC/MS Temperature Parameters and Target Ions for Individual Analytes

Target Analyte Ions Initial 

Temp 

(

oC)

Initial 

Time 

(min)

Rate 

(

oC 

/min)

Final 

Temp 

(

oC)

Rate 

(

oC 

/min)

Final 

Temp 

(

oC)

Hold 

Time 

(min)

Rate 

(

oC 

/min)

Hold 

Temp 

(

oC)

Hold 

Time 

(min)

Run 

Time 

(min)

Cocaine

PCP

182/185

200/205 150 1.0 25 250 10 285 1.5 15 300 2.0 13

Codeine

Morphine

371/374

429/432 150 1.0 25 250 10 285 2.5 25 300 1.0 12.6

Amphetamine

Methamphetamine

240/244

254/258 120 1.0 5 150 0 0 2.0 30 300 1.0 15

Carboxy-THC 371/374 120 0.5 5 150 25 250 0.5 10 300 3.0 13

Selected ion chromatograms for each target analyte (fig. 5-11) are in the appendix section.

2

5
26

The following protocol was used when analyzing all four sets of saliva samples. Single analyses 

of each of the five standards were run followed by analyses of samples within the set in 

ascending order of concentration. The samples were then run in descending order, followed by 

the analysis of the five standards in reverse order. By combining the data of the standards run 

before and after the samples, a composite linear regression (y = mx + b) was calculated for each 

of the target analytes, which was used to convert the measured intensity ratios of analytes to 

weight ratios. The weight ratios were then used along with the amounts of internal standards 

added to calculate the analyte concentration in each sample.

3.1.4 Device Test Procedures

All the devices evaluated utilize lateral flow chromatographic immunoassays. These devices

work via the same principles, utilizing monoclonal antibodies to selectively detect elevated 

levels of specific drugs in human oral fluid. Each device was tested with 4 sets of saliva samples 

until a LOD could be determined for each analyte. The devices varied in the volume of saliva 

required to run the test, the time taken to read the test results, and the analytes detected. Table 14

shows the various criteria for the individual tests.

Table 14. Criteria for Oral Fluid Drug Testing Devices

Oral Fluid 

Drugs Testing 

Device

Volume of 

Saliva 

Required

Designated 

dropping area

Read 

Results 

after

Analyte(s) detected

Oral Fluid Drug 

Screen Device

5 drops per 

well 2 adjacent wells 10 min

PCP, Cocaine, Codeine, Morphine, 

Amphetamine, Methamphetamine, 

Carboxy-THC.

ORAL 

SCREEN Saliva 

4

4 drops 1 well 15 min Cocaine, Codeine, Morphine, 

Methamphetamine, THC.

iScreen Oral 

Fluid Device 6 15 drops 1 well 10 min

PCP, Cocaine, Codeine, Morphine, 

Amphetamine, Methamphetamine, 

Carboxy-THC.

iScreen Oral 

Fluid Device 6 30 drops Plastic cup 10 min

PCP, Cocaine, Codeine, Morphine, 

Amphetamine, Methamphetamine,

Carboxy-THC.THC

Oratect II 15 drops Cotton tip 5 min

PCP, Cocaine, Morphine, 

Amphetamine, Methamphetamine, 

Carboxy-THC.THC

3.2 Device Testing Results

Oral Fluid Drug Screen Device

The Oral Fluid Drug Screen Device is very compact (7 cm x 4 cm) and has spaces available to 

record both the date and the identification of the sample being tested. The kit has two wells in 

which the sample is placed (5 drops per well) and two corresponding windows in which the test 

results could be viewed. Window one indicated the presence or absence of cocaine, 
27

methamphetamine and PCP and window two, THC, opiates and amphetamine. This particular 

device did not differentiate between codeine and morphine; it only detected the group opiates. 

Each window has a control line which is required to be present in order for the test results to be 

validated. Each detection window is labeled with the target analyte. A negative result is shown 

by the presence of a pink line next to the named target analyte, indicating that the analyte is not 

present in the sample at concentrations above or equal to its LOD. A positive result is shown by 

the absence of a pink line next to the target analyte, indicating that the analyte is present in the 

sample at a concentration equal to or greater than its LOD. Table 15 shows the limit of detection 

obtained for each analyte and the manufacturers claimed limit of detection. The results from the 

analysis are subject to interpretation. Upon a consensus of two people, the LOD for both cocaine 

and PCP was 5 ng/mL lower than the manufacturer’s claimed value. The lines for the opiates 

were very faint and at times difficult to determine. The LOD for opiates was determined at 

5 ng/mL higher than the manufacturer’s claimed value. Amphetamine, also showing very faint 

lines for a negative result, had an LOD as claimed by the manufacturer, whereas the LOD for

methamphetamine was 20 ng/mL less than the claimed value. Carboxy-THC results showed the 

greatest variance from the manufacturer’s claims with an LOD 28 ng/mL higher than claimed. It 

was also noted that the lines for carboxy-THC were consistently faint throughout analysis. 

Because the determination of results is open to interpretation by the individual analyst, the 

differences between the manufacturer’s claims and the results are insignificant, with the 

exception of carboxy-THC.

Table 15. Limit of Detection for Analytes using Oral Fluid Drug Screen Device

Target Analyte LOD (ng/mL) Manufacturer’s LOD (ng/mL)

Cocaine 15 20

PCP 5 10

Codeine 45 40

Morphine 45 40

Amphetamine 50 50

Methamphetamine 30 50

Carboxy-THC 40 12

Oral Screen Saliva 4

The Oral Screen Saliva 4 was also compact (2.5 cm x 10 cm) but only detected 4 analytes; THC, 

cocaine, opiates, and methamphetamine. The device had a space for the ID of the sample to be 

recorded, a single well for introduction of saliva (4 drops), and a viewing window to observe the 

results. This device worked in the same manner as the Oral Fluid Drug Screen Device in that the 

presence of a control line was required to validate the test, the appearance of a pink line indicated 

a negative result, and the absence of the pink line indicated a positive result. Table 16 shows the 

LOD’s obtained for each of the 4 target analytes and the manufacturers claimed LOD’s. These 

results represent a consensus of two people. The LOD for both opiates and carboxy-THC were 

the same as the manufacturers claimed value. The LOD for cocaine was 10 ng/mL lower and the 

LOD for methamphetamine was 10 ng/mL higher than the given values. Differences between 

the manufacturer’s claimed LOD values and the test results are insignificant due to the possible 

differences in interpretation of results. With the exception of the opiate, line all the lines on this 
28

test kit were very clear and easy to read. The opiate line, however, was very faint when no 

opiates were present, and results would be subject to interpretation depending on the particular 

analyst.

Table 16. Limit of Detection for Analytes using ORAL SCREEN Saliva 4

Target Analyte LOD (ng/mL) Manufacturer’s LOD (ng/mL)

Cocaine 5 15

PCP N/A N/A

Opiates 10 10

Amphetamine N/A N/A

Methamphetamine 60 50

Carboxy-THC 50 50

iScreen Oral Fluid Devices

During the analysis of the iScreen Oral Fluid Devices a second batch was ordered. When the 

second batch was received it became apparent that the manufacturer had altered the outer casing 

surrounding the assay component.

a) Set A (3.25 cm x 10 cm) utilized large well in which 15 drops of saliva were to be 

applied.

b) Set B (93 cm x 12 cm) utilized sponge applicator which was to be soaked in 30 drops of 

saliva to reach saturation.

Both devices tested for 6 analytes; cocaine, methamphetamine, PCP, THC, opiates, and 

amphetamines via the same basic principles. We found cocaine, PCP, codeine, and morphine all 

had LOD values lower than the manufacturers claimed value, 15 ng/mL, 5 ng/mL, 20 ng/mL,

and 20 ng/mL respectively. Methamphetamine was found to have the same LOD value while 

amphetamine and carboxy-THC had higher LOD values by 10 ng/mL and 8 ng/mL respectively. 

Because of possible difference in interpretation, the differences between our recorded LOD 

values and those claimed by the manufacturer were small and were considered to be 

insignificant. The lines for both amphetamine and methamphetamine were consistently very 

faint for this drug testing device. As a result of this, interpretation was difficult and subject to 

large uncertainties (see table 17).

Table 17. Limit of Detection for Analytes using iScreen Oral Fluid Device 6

Target Analyte LOD (ng/mL) Manufacturer’s LOD (ng/mL)

Cocaine 5 20

PCP 5 10

Codeine 20 40

Morphine 20 40

Amphetamine 60 50

Methamphetamine 50 50

Carboxy-THC 20 12
29

Oratect II

The Oratect II (1.75 cm x 13 cm) provides a space for both the date and the sample ID to be 

recorded. It detects six analytes; methamphetamine, carboxy-THC, cocaine, amphetamine, 

opiates, and PCP. The device consists of a sponge pad at the end where the saliva is to be 

applied (15 drops) and two windows to view the test results. There is also a plastic cover to put 

over the sponge pad once the saliva has been applied to it. The carboxy-THC and amphetamine 

lines were found to be extremely faint with the Oratect II. Cocaine and morphine both had 

LOD’s lower than the claimed value, 10 ng/mL and 30 ng/mL respectively. The LOD for PCP 

was as claimed and methamphetamine and carboxy-THC both had higher LOD’s by 25 ng/mL 

and 60 ng/mL respectively. The Oratect II failed to produce a positive result for all 

concentrations of amphetamine tested. A lack of positive result for amphetamine and the 

dramatically increased LOD for carboxy-THC are significantly different from the manufacturer’s 

claimed LOD values (see table 18).

Table 18. Limit of Detection for Analytes using Oratect II

Target Analyte LOD (ng/mL) Manufacturer’s LOD (ng/mL)

Cocaine 10 20

PCP 5 4

Codeine N/A N/A

Morphine 10 40

Amphetamine >100 25

Methamphetamine 50 25

Carboxy-THC 100 40

3.3 Interference Testing

Each of the devices were tested for cross reactivity with 5 over the-counter drugs and with 

caffeine, a substance commonly found in human saliva (shown in table 19). Solutions were 

made at 100 μg/mL and evaluated using the test kits. Acetaminophen, ibuprofen, aspirin, 

naproxen sodium, and caffeine all produced negative test results for all analyte classes and thus 

no further testing was carried out. Pseudoephedrine produced a positive result with for all 4 

devices and testing was repeated using a more dilute solution, 10 μg/mL. The results from this 

analysis were negative for all devices and for all analyte classes.
30

Table 19. Results from Cross Reactivity Testing

Oral Fluid Drug 

Screen Device

ORAL SCREEN 

Saliva 4

iScreen Oral 

Fluid Device 6

Oratect II

Acetaminophen

100μg/mL

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Ibuprofen 

100 μg/mL

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Aspirin 

100 μg/mL

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Naproxen Sodium 

100 μg/mL

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Caffeine Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Pseudoephedrine 

100 μg/mL

Positive for 

Amphetamines & 

Methamphetamine

Positive for 

Methamphetamine

Positive for 

Amphetamines & 

Methamphetamine

Positive for 

Amphetamines & 

Methamphetamine

Pseudoephedrine 

10 μg/mL 

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

Negative for all 

analytes

3.4 Results from GC/MS Analysis

Method linearity is defined by results that are directly proportional to analyte concentration 

within a given range. The linearity for each method was established by plotting the response ratio 

(analyte response/internal standard response) against the actual weight ratio (analyte 

concentration/internal standard concentration). The fit parameter (R2) is an indicator of the 

linearity of the data. The R2values for each analyte is shown in table 20 along with the % 

recovery values for each analyte.

Table 20. R

2 Values and % Recovery for the 7 Analytes

Analyte R

2 Value Recovery 

Cocaine 0.988 95 %

PCP 0.999 95 %

Codeine 0.999 103 %

Morphine 0.996 93 %

Amphetamine 0.971 92 %

Methamphetamine 0.989 90 %

Carboxy-THC 0.977 46 %

3.5 Summary of Results

It is important to acknowledge that the manufacturers of each point-of-collection drug-testing kit 

state within the instruction sheet that the assay provides only a preliminary analytical test result. 

A more specific alternate chemical method must be used for confirmation. Gas chromatography/ 

mass spectrometry (GC/MS) and gas chromatography/tandem mass spectrometry (GC/MS/MS) 

are the two preferred confirmatory techniques. In general, the ability of each of the kits to detect 

drugs of abuse at relatively low concentrations (ng/mL) was good. The size of the kits and the 
31

ease of carrying out each test would allow use in a wide variety of environments. A few 

discrepancies in the interpretation of the results were apparent, and these discrepancies would be 

exacerbated in poor working conditions that might be encountered in field use (e.g., poor lighting 

conditions). 

Small discrepancies were also apparent between the LOD’s determined for each analyte and the 

LOD value claimed by the manufacturer. In general, these discrepancies were of minor 

significance. Due to the subjective nature of the interpretation of results, small discrepancies in 

results are to be expected.

If the LOD is equal to or lower than claimed by the manufacturer, (i.e., more sensitive than 

claimed), lower levels of drugs will be detected. As indicated by manufacturers it is essential 

that all positive results are confirmed by GC/MS or GC/MS/MS. Higher LOD’s result in false 

negatives, which occur when the kits are less sensitive than stated, such discrepancies are of 

much greater concern.

THC-COOH was the most difficult analyte to detect. The observed LOD was higher than the 

manufacturer’s LOD by a factor of 2.5 for Oratect II, by a factor of 3 for the Oral Fluid Drug 

Screen Device, and by a factor of 1.3 with iScreen Oral Fluid Device. For the Oratect II devices, 

limits of detection for amphetamine were >4 times higher than claimed, and LODs for 

methamphetamine were 2 times higher than claimed. In all of these cases false negative results 

would be obtained.
32

APPENDIX

Figure 5. Selected ion Chromatograms by GC/MS for Phencyclidine and Phen-D5-cyclidine
33

Figure 6. Selected ion Chromatograms by GC/MS for Cocaine and Cocaine-D3
34

Figure 7. Selected ion Chromatograms by GC/MS for Codeine and Codeine-D3
35

Figure 8. Selected ion Chromatograms by GC/MS for Morphine and Morphine-D3
36

Figure 9. Selected ion Chromatograms by GC/MS for Amphetamine and Amphetamine-D5
37

Figure 10. Selected ion Chromatograms by GC/MS for Methamphetamine and 

Methamphetamine-D5
38

Figure 11. Selected ion Chromatograms by GC/MS for Tetrahydrocannabinol Carboxylic 

Acid and Tetrahydrocannabinol-D3.carboxylic Acid
39

1. 2. 3. 4. 5. 

Figure 12. Point of Collection Oral Fluid Drug Testing Devices

Table 21. Point of Collection Oral Fluid Drug Testing Devices and the Results Shown in Figure 12

Point of Collection 

Drug Testing Device

Saliva Spiked 

with Concentration PositiveResult(s)

Negative 

Result(s)

1. Oral Fluid Drug Screen 

Device Amphetamine

Methamphetamine 100 ng/mL AmphetamineMethamphetamine

All other 

analytes

2. Oral Screen 4 Carboxy -THC 50 ng/mL Carboxy -THC All other 

analytes

3. iScreen Cocaine

PCP 25 ng/mL CocainePCP

All other 

analytes

4. iScreen Blank Saliva N/A None All Analytes

5. Oratect II Methadone

Codeine 20 ng/mL MethadoneCodeine

All other 

analytes