Systematic Approach Guide Laboratory Fire Standards and Protocols Committee 

Version 1.0 September 2004 

Designated E xxxx-xx 

Standard Guide for a Systematic Approach to the Analysis of FireRelated Samples for Ignitable Liquids and their Residues 

Version 1.0 

Developed by the 

Laboratory Fire Standards and Protocols Committee 

Scientific Working Group for Fire and Explosions 

1. Scope 

1.1. This guide describes a systematic approach for the analyses of fire debris and 

liquid samples for the presence of ignitable liquids and their residues. 

1.2. This guide does not address the specific methodologies necessary for the 

extraction of debris, the techniques of instrumental analysis, or the interpretation 

of analytical data. 

1.3. This guide does not attempt to address all the issues regarding sample analyses. 

There may be additional tests or analyses that can be performed to provide 

further discrimination and characterization of samples. 

1.4. This guide does not address the necessity for laboratory notes and the proper 

documentation required for all forensic examinations. 

1.5. This guide does not purport to address all of the safety concerns, if any, 

associated with its use. It is the responsibility of the user of this guide to establish 

appropriate safety and health practices and determine the applicability of 

regulatory limitations prior to use. 

2. Referenced Documents 

2.1. ASTM Standards: 

E 1386 Practice for the Separation and Concentration of Ignitable Liquid Residues 

from Fire Debris Samples by Solvent Extraction 

E 1387 Test Method for Ignitable Liquid Residues in Extracts from Fire Debris 

Samples by Gas Chromatography 

E 1388 Practice for Sampling of Headspace Vapors from Fire Debris Samples 

E 1412 Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples 

by Passive Headspace Concentration With Activated Charcoal 

E 1413 Practice for Separation and Concentration of Ignitable Liquid Residues from 

Fire Debris Samples by Dynamic Headspace Concentration 

E 1459 Guide for Physical Evidence Labeling and Related Documentation 

E 1492 Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a 

Forensic Science Laboratory 

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E 1618 Test Method for Ignitable Liquid Residues in Extracts from Fire Debris 

Samples by Gas Chromatography-Mass Spectrometry 

E 2154 Practice for the Separation and Concentration of Ignitable Liquid Residues 

from Fire Debris Samples by Passive Headspace Concentration with Solid 

Phase Microextraction (SPME) 

E xxxx Standard Practice for Archiving Ignitable Liquid Residues in Extracts from 

Fire Debris Samples and Questioned Liquid Samples Submitted for Ignitable 

Liquid Analysis 

3. Summary of Guide 

3.1. The analysis of fire debris samples should be conducted systematically. There are 

a variety of established methods for the extraction of fire debris samples. This 

guide provides an organized approach for the examination and analysis of this 

type of evidence. 

4. Significance and Use 

4.1. This guide provides an efficient and comprehensive analytical scheme for the 

analysis of fire debris samples. 

4.2. This guide is to be used in conjunction with the referenced documents. The 

analyst must be familiar with the limitations and applicability of each technique. 

5. Evidence handling 

5.1. Ensure that chain of custody is intact and properly identifies the evidence. 

Resolve deficiencies as necessary. 

5.2. Ensure that the evidence is properly packaged and resolve deficiencies as 

necessary. 

5.3. Ensure that accompanying documentation properly describes the evidence. 

Resolve deficiencies as necessary. 

6. Ensure proper storage 

6.1. Items believed to contain substrate materials likely to contribute to the 

degradation of petroleum products, such as vegetation or soil should be 

refrigerated or frozen until the time of analysis if the analysis cannot be expedited. 

6.2. Items of evidence shall be stored in a manner that will avoid contamination. 

6.3. Following analysis, the original sample and extracts generated during sample 

preparation should be preserved. 

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7. Investigative Background 

7.1. Information from scene investigators can aid the analyst in understanding the 

events of the incident, can assist in evaluating the evidence submitted, and can 

help in determining which tests or test methods might be appropriate. 

7.2. Information from the investigator that may affect the analytical scheme should be 

obtained prior to analysis when possible. This type of information may include 

sample location, suppression techniques, knowledge of ignitable liquids inherent 

to the scene, the types of examinations requested, and the suspected presence of 

materials that may require specialized testing. 

7.3. Identify special considerations that may affect the initial approach to the evidence. 

7.4. To ensure adherence to universal precautions, attempt to determine if any 

biological or chemical hazards are present. Determine if other evidence of value 

could be potentially derived from the evidence, such as DNA, latent prints, or 

other trace evidence. 

7.5. When multiple forensic disciplines will be involved, coordinate the overall 

approach to the analysis with the investigator and other analysts. Determining the 

sequence of multiple examinations will depend upon the priorities of the 

investigation, the nature of the evidence, and the requested examinations. 

8. Initial Assessment of Evidence 

8.1. A brief visual assessment of each item should be conducted. Preliminary 

identification of contents can provide direction to the selection of an analytical 

scheme and suggest complexities that may be encountered in the analytical data 

obtained. 

8.1.1. If the evidence is determined to contain one or more of the following 

types of materials, additional examinations will likely be required. 

8.1.1.1. Flare residues. 

8.1.1.2. Incendiary residues. 

8.1.1.3. Device remnants. 

8.1.2. Different substrates may produce a variety of interfering products; 

therefore, the substrate material should be noted when possible. 

8.1.3. If the matrix is excessively charred or if excessive water is present, it may 

affect the recovery of ignitable liquid residues. 

8.1.4. Note the presence of extraneous materials in samples such as additional 

layers of packaging or disposable gloves used for collection. Such items 

shall be separated from the evidence prior to processing. 

8.1.5. Given the unknown nature and origin of most samples, olfactory analysis 

may pose a health risk and is not recommended. Obvious odors should be 

noted because they may provide an indication of the type of ignitable 

liquid residues that are present in the sample and may aid in the selection 

of an extraction scheme. 

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9. Comparison Samples 

9.1. Comparison samples may provide information that can aid in the interpretation of 

data obtained from fire debris samples. Examples of such information include the 

effects of a soil on the degradation of a petroleum product, the presence of 

incidental ignitable liquids or background products in the substrate, and the nature 

of pyrolysis and combustion products released by the material being tested. 

10. Sample Preparation 

10.1. Liquid Sample Assessment Techniques: 

10.1.1. Liquid samples may be submitted by fire investigators for identification or 

comparison. These samples may not always be submitted in their original 

containers. Ignitable liquids, if present, may be in their original state or 

mixed with other liquids. The ideal sampling procedure will provide a 

representative sample of the liquid in its entirety. There is no sampling 

procedure that will perform ideally for all samples. Preliminary assessment 

of the sample can aid the analyst in determining the best sampling 

procedure to use. These assessment techniques may include many 

common chemical and physical tests. 

10.1.2. Ignitability: Observing a sample’s ignition and burning characteristics is a 

valuable assessment technique. Some of the ignition and burning 

characteristics that may be of value include ease of ignition, flame color, 

and smoke characteristics. While flash point (flammability or 

combustibility) may sometimes be determined using a flash point 

apparatus, such analyses are not generally required. 

10.1.3. Miscibility: Miscibility testing can be used for preliminary assessment of 

liquids. Most ignitable petroleum products are immiscible with water. 

Many common oxygenates are miscible with water. Therefore, if a sample 

contains more than one phase, individual sampling of each phase should 

be considered. 

10.1.4. Other tests: Additional types of testing may be useful in characterizing an 

unknown liquid. These may include pH, density, freezing point, boiling 

point, refractive index and other tests deemed necessary. 

10.2. Liquid Sample Preparation Techniques for Gas Chromatographic Analysis: 

10.2.1. Headspace Sampling (ASTM E 1388): Headspace sampling is particularly 

useful for highly volatile liquid samples. 

10.2.2. Direct Injection: This method can provide the best representation of a 

liquid’s components, however, it is not generally recommended for 

aqueous samples. This technique is not typically amenable to automated 

analyses. 

10.2.3. Simple Dilution: Simple dilution is the most common technique for 

preparation of liquid samples. A 1% solution in a miscible solvent is 

generally recommended. One disadvantage of this technique is that the 

solvent peak may mask components of interest. 

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10.2.4. Liquid-Liquid Extraction: Liquid-Liquid extraction is a technique used to 

extract ignitable liquid residues from aqueous samples. An appropriate 

organic solvent is added to the aqueous sample and the sample is agitated. 

Petroleum products and other organic components will be extracted into 

the organic phase. The organic layer is then isolated, concentrated if 

necessary, and analyzed. 

10.2.5. Passive Headspace Concentration (ASTM E-1412): Passive headspace 

concentration with activated charcoal can be used to extract liquid 

samples. It should be noted that in the presence of high concentrations of 

ignitable liquids, the chromatographic data may be distorted. 

10.2.6. Solid Phase Microextraction (SPME) (ASTM E-2154): SPME can be used 

for headspace sampling of liquids. It should be noted that in the presence 

of high concentrations of ignitable liquids, the chromatographic data may 

be distorted. 

10.3. Debris Assessment Techniques: 

10.3.1. Assessment Considerations: Most samples submitted for analysis by fire 

investigators are in the form of fire debris collected in the course of scene 

investigations. These samples may be in various states of charring, 

destruction, or decomposition due to fire damage, fire suppression, and 

packaging. Ignitable liquid residues, if present, may range from very low to 

very high concentrations. The ideal extraction procedure will provide a 

representative sample of the volatile components with minimal 

contributions from matrix materials. There is no single extraction 

technique or set of parameters within a technique that is ideal for all 

samples. Some samples may require more than one extraction or analysis 

before a conclusion can be made. For this reason, the least destructive 

procedures should be used first. Preliminary assessment of the samples to 

determine relative concentration can aid the analyst in determining the 

best extraction procedure and parameters for a given sample. 

10.3.1.1. The analysis procedures for simple matrices including nonporous materials and small samples may differ from that of more complex 

matrices (e.g. carpet, pad, plastics, clothing, printed paper, floor tile, wood, 

and “unidentifiable” charred debris). 

10.3.2. Headspace Sampling (ASTM E-1388): Headspace analysis is simple, quick, 

and non-destructive. Headspace sampling is an ideal alternative for 

olfactory techniques in screening debris samples. The headspace technique 

can provide the analyst with preliminary information concerning the 

presence of an ignitable liquid, its classification, and its relative 

concentration. Headspace sampling is also appropriate for the analysis of 

very volatile components such as ethers or alcohols. The disadvantages of 

this technique include limited sensitivity and the inability to recover less 

volatile components. 

10.3.3. Solid Phase Microextraction (SPME) (ASTM E-2154): SPME sampling is 

an ideal alternative for olfactory techniques in screening debris samples. 

SPME is a simple technique that can provide the analyst with preliminary 

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information concerning the presence of an ignitable liquid, its 

classification, and its relative concentration. 

10.4. Debris Extraction Techniques for Gas Chromatographic Analysis: 

10.4.1. Passive Headspace Concentration (ASTM E-1412): Passive headspace 

concentration using activated charcoal is a versatile, non-destructive 

technique offering numerous advantages and is, therefore, the initial 

method of extraction for most analyses. This is an efficient technique that 

is highly sensitive and can recover a broad range of compounds. It 

requires minimal sample manipulation, has very low potential for sample 

contamination, and is amenable to sample preservation and resampling. It 

should be noted that recovery might be less than ideal in the presence of a 

highly adsorbent matrix. Determining the optimum parameters is critical 

for obtaining data representative of any ignitable liquid residue. 

10.4.2. Dynamic Headspace Concentration (ASTM E-1413). Dynamic headspace 

concentration using activated charcoal is highly sensitive and can recover a 

broad range of compounds. Total extraction time is relatively short 

however, it is a labor-intensive technique. Special consideration must be 

given to minimizing the potential for sample contamination. This 

technique may be considered destructive, although, it is amenable to 

sample preservation. It should be noted that recovery might be less than 

ideal in the presence of a highly adsorbent matrix. Determining the 

optimum parameters is critical for obtaining data representative of any 

ignitable liquid residue. 

10.4.3. Solvent Extraction (ASTM E-1386): Solvent extraction is a technique 

capable of extracting both volatile and nonvolatile compounds across a 

broad range with minimal sample discrimination. This method is efficient 

in the recovery of compounds of interest from a highly adsorbent matrix. 

Solvent extraction is an efficient technique for isolating all soluble 

compounds. It might result in the extraction of extraneous compounds 

and cause complexities in the analytical data. Solvent extraction may be 

warranted when definitive information is required for semi-volatile 

components. A loss of low boiling point compounds may occur during 

sample concentration. This is a destructive technique therefore, only a 

portion of the sample should be used for solvent extractions. 

11. Instrumental Analysis 

11.1. In general, analytical techniques based upon separation and detection of individual 

components are required. 

11.2. Gas Chromatography (Flame Ionization Detector): Gas chromatography is an 

instrumental technique capable of resolving a wide range of organic compounds. 

A flame ionization detector (FID) is sensitive, universal and non-specific. This 

technique may be used for the identification and classification of complex 

ignitable liquids and their residues. It is not sufficient for the identification of all 

ignitable liquids or in cases of high concentrations of interfering compounds. 

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11.3. Gas Chromatography-Mass Spectrometry: Gas chromatography-mass 

spectrometry (GC-MS) is an instrumental technique capable of resolving a wide 

range of organic compounds and providing structural information about 

individual components. This technique may be used for the identification of single 

component ignitable liquids and for samples that contain high concentrations of 

interfering compounds. 

11.4. Other Instrumental Methods: Other instrumental methods may be useful for the 

characterization or identification of ignitable liquids. The use of other methods 

will be dictated by the investigative needs of the case and the unique 

characteristics of the sample. 

12. Sample Preservation 

12.1. Whenever possible, samples should be preserved for potential reanalysis. 

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