1、Designation: E1618 11Standard Test Method forIgnitable Liquid Residues in Extracts from Fire DebrisSamples by Gas Chromatography-Mass Spectrometry1This standard is issued under the fixed designation E1618; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the identification of residues ofignitable liquids in extra
3、cts from fire debris samples. Extrac-tion procedures are described in the referenced documents.1.2 Although this test method is suitable for all samples, itis especially appropriate for extracts that contain high back-ground levels of substrate materials or pyrolysis and combus-tion products. This t
4、est method is also suitable for the identi-fication of single compounds, simple mixtures, or non-petroleum based ignitable liquids.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address
5、 all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1386 Practice fo
6、r Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Solvent ExtractionE1388 Practice for Sampling of Headspace Vapors fromFire Debris SamplesE1412 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Passive Headspace Concen-tration With Activated Charcoal
7、E1413 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Dy-namic Headspace ConcentrationE2154 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by PassiveHeadspace Concentration with Solid Phase Microext
8、rac-tion (SPME)E2451 Practice for Preserving Ignitable Liquids and Ignit-able Liquid Residue Extracts from Fire Debris Samples3. Summary of Test Method3.1 The sample is analyzed with a gas chromatograph (GC)which is interfaced to a mass spectrometer (MS) and a datasystem (DS) capable of storing and
9、manipulating chromato-graphic and mass spectral data.3.2 Post-run data analysis generates extracted ion profiles(mass chromatograms) characteristic of the chemical com-pound types commonly found in ignitable liquids.Additionally,specific chemical components (target compounds) may beidentified by the
10、ir mass spectra and retention times. Semi-quantitative determination of target compounds which areidentified by mass spectra and retention time may be used todevelop target compound chromatograms (TCCs).3.2.1 The total ion chromatogram (TIC), extracted ionprofiles (EIP) for the alkane, alkene, alcoh
11、ol, aromatic, cycloal-kane, ester, ketone and polynuclear aromatic compound types,or TCCs, or combination thereof, are evaluated by visualpattern matching against known reference ignitable liquids.3.2.2 Ignitable liquids may be grouped into one of sevenmajor classifications or one miscellaneous clas
12、s, as describedin this test method.4. Significance and Use4.1 The identification of an ignitable liquid residue insamples from a fire scene can support the field investigatorsopinion regarding the origin, fuel load, and incendiary natureof the fire.4.1.1 The identification of an ignitable liquid res
13、idue in afire scene does not necessarily lead to the conclusion that a firewas incendiary in nature. Further investigation may reveal alegitimate reason for the presence of ignitable liquid residues.1This test method is under the jurisdiction ofASTM Committee E30 on ForensicSciences and is the direc
14、t responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 1994. Last previous edition approved in 2010 as E1618 10. DOI:10.1520/E1618-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact A
15、STM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.2 Because of the volati
16、lity of ignitable liquids andvariations in sampling techniques, the absence of detectablequantities of ignitable liquid residues does not necessarily leadto the conclusion that ignitable liquids were not present at thefire scene.4.2 Materials normally found in a building, upon exposureto the heat of
17、 a fire, will form pyrolysis and combustionproducts. Extracted ion profiling and target compound identi-fication techniques described herein may facilitate the identi-fication of an ignitable liquid in the extract by reducinginterference by components generated as products of pyrolysis.5. Apparatus5
18、.1 Gas ChromatographA chromatograph capable of us-ing capillary columns and being interfaced to a mass spectrom-eter.5.1.1 Sample Inlet SystemA sample inlet system that canbe operated in either split or splitless mode with capillarycolumns; the inlet system may use on-column technology.5.1.2 ColumnA
19、 capillary, bonded phase, methylsiliconeor phenylmethylsilicone column or equivalent. Any columnlength or temperature program conditions may be used pro-vided that each component of the test mixture (see 6.4)isadequately separated.5.1.3 GC OvenA column oven capable of reproducibletemperature program
20、 operation in the range from 50 to 300C.5.2 Mass SpectrometerCapable of acquiring mass spectrafrom m/z 40 to m/z 400 with unit resolution or better, withcontinuous data output. Values above m/z 40 may not besufficient to detect or identify some lower molecular weightcompounds; for example, methanol,
21、 ethanol, acetone.5.2.1 SensitivityThe system shall be capable of detectingeach component of the test mixture (see 6.4) and providingsufficient ion intensity data to identify each component, eitherby computer library search or by comparison with referencespectra.5.3 Data StationA computerized data s
22、tation, capable ofstoring time sequenced mass spectral data from sample runs.5.3.1 Data HandlingThe data system shall be capable ofperforming, either through its operating system or by userprogramming, various data handling functions, including inputand storage of sample data files, generation of ex
23、tracted ionprofiles, searching data files for selected compounds, andqualitative and semi-quantitative compound analysis.5.3.2 Mass Spectral LibrariesThe system shall be capableof retrieving a specified mass spectrum from a data file andcomparing it against a library of mass spectra available to the
24、data system. This capability is considered an aid to the analyst,who will use it in conjunction with chromatographic data andknown reference materials to identify unknown components.5.4 Syringes:5.4.1 For liquid samples, a syringe capable of introducing asample size in the range from 0.1 to 10.0 L.5
25、.4.2 For gas samples, a gas-tight syringe capable ofintroducing a sample size in the range of 0.5 to 5 mL.6. Chemicals, Reagents, and Reference Materials6.1 Purity of ReagentsReagent grade or better chemicalsshall be used in all tests. Unless otherwise indicated, it isintended that all reagents conf
26、orm to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety where such specifications are available. Other gradesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the de
27、termination.6.2 Solvent/DiluentCarbon disulfide, diethyl ether, pen-tane, or other solvent that will not interfere with the analysis.It is generally desirable to use a solvent whose volatility greatlyexceeds that of the solute to facilitate sample concentration byevaporation, if necessary.6.2.1 Use
28、of a heavier solvent, such as toluene or tetrachlo-roethylene, is sometimes necessary when the compounds ofinterest have low molecular weights.6.3 Carrier GasHelium or hydrogen of purity 99.995 %or higher.6.4 Test MixtureThe test mixture shall consist of a mini-mum of the even-numbered normal alkane
29、s (ranging fromn-octane through n-eicosane), methylbenzene (toluene), 1,4-dimethylbenzene (p-xylene), 1-methyl-2-ethylbenzene (o-ethyltoluene), 1-methyl-3-ethylbenzene (m-ethyltoluene), and1,2,4-trimethylbenzene (pseudocumene). Additional com-pounds may be included at the discretion of the analyst.
30、Thefinal test solution is prepared by diluting the above mixturesuch that the concentration of each component is 0.005 %volume/volume (0.05 microliters/milliliter) in the chosen sol-vent (see 6.2). A typical chromatogram of the test mixture isshown in Fig. 1.6.5 Reference Ignitable LiquidsIgnitable
31、liquids shall beavailable for the various ignitable liquids represented in Table1.6.5.1 Typically, reference ignitable liquids are diluted1:1000 in an appropriate solvent. Depending on the columncapacity and injection technique, ignitable liquid solutions canbe made somewhat more concentrated to ens
32、ure detection ofminor compounds.6.5.2 Certified ignitable liquid standards are not necessary.Most reference ignitable liquids can be obtained from com-mercial and retail sources.7. Equipment Calibration and Maintenance7.1 Verify the consistent performance of the chromato-graphic instrument by using
33、blanks and known concentrationsof either prepared test mixture or other known ignitable liquids.Optimize gas flows periodically.7.2 Tune and calibrate mass spectrometer.7.2.1 Tune the mass spectrometer using perfluorotribu-tylamine (PFTBA), or another appropriate calibration standard,according to th
34、e instrument manufacturers specifications,prior to use. This should be done at least every day that theinstrument is used or per manufacturers recommendations.7.2.2 Maintain tuning documentation as a portion of thequality control documentation.7.3 Cleaning the equipment.7.3.1 Change septa and clean
35、or replace injector liners on aperiodic basis to avoid sample contamination by carryover ofresidual material from previous sample injections.E1618 1128. Sample Handling Procedure8.1 Only samples of appropriate dilution should be analyzedon a GC-MS system.8.2 Methods for isolating ignitable liquid re
36、sidues from firedebris for analysis by this test method are described inPractices E1386, E1388, E1412, E1413, and E2154.8.3 Because of the volatility of solvents and analytes, caremust be taken to ensure that samples do not evaporate orotherwise change composition prior to analysis. Septum sealvials
37、 may be used for short term storage of any solvents orextracts. See Annex A1 for sample and extract storage guid-ance.8.3.1 Avoid the use of water as a sealant.8.4 Analyze solvent blanks at least once each day that theinstrument is used; maintain these analysis records. This willverify the purity of
38、 the solvent and potentially detect carryoveror contamination.8.5 Clean syringes thoroughly between injections to ensureno carryover.FIG. 1 Test Mixture Containing C8-C20 Normal Hydrocarbons, toluene, p-xylene, o-ethyltoluene, m-ethyltoluene, and 1,2,4-trimethylbenzeneTABLE 1 Ignitable Liquid Classi
39、fication SchemeAClass Light (C4-C9) Medium (C8-C13) Heavy (C9-C20+)Gasoline-all brands,including gasohol and E85Fresh gasoline is typically in the range C4-C12Petroleum Distillates(including De-Aromatized)Petroleum EtherSome Cigarette Lighter FluidsSome Camping FuelsSome Charcoal StartersBSome Paint
40、 ThinnersSome Dry Cleaning SolventsKeroseneDiesel FuelSome Jet FuelsSome Charcoal StartersIsoparaffinic ProductsAviation GasSome Specialty SolventsSome Charcoal StartersSome Paint ThinnersSome Copier TonersSome Commercial SpecialtySolventsAromatic ProductsSome Paint and VarnishRemoversSome Automotiv
41、e Parts CleanersXylenes, Toluene-based products.Some Automotive Parts CleanersSpecialty Cleaning SolventsSome Insecticide VehiclesFuel AdditivesSome InsecticideVehiclesIndustrial CleaningSolventsNaphthenic- Paraffinic ProductsCyclohexane basedsolvents/productsSome Charcoal StartersSome Insecticide V
42、ehiclesSome Lamp OilsSome InsecticideVehiclesSome Lamp OilsIndustrial SolventsNormal-Alkanes ProductsSolventsPentaneHexaneHeptaneSome Candle OilsSome Copier TonersSome Candle OilsCarbonless FormsSome Copier TonersOxygenated SolventsAlcoholsKetonesSome Lacquer ThinnersFuel AdditivesSurface Preparatio
43、n SolventsSome Lacquer ThinnersSome Industrial SolventsMetal Cleaners/Gloss RemoversOthers-MiscellaneousSingle Component ProductsSome Blended ProductsSome Enamel ReducersTurpentine ProductsSome Blended ProductsSome Specialty ProductsSome Blended ProductsSome Specialty ProductsAThe products listed in
44、 the various classes of Table 1 are examples of known commercial uses of these ignitable liquids. These examples are not intended to beall-inclusive. Reference literature materials may be used to provide more specific examples of each classification.BMany of the examples can be prefaced by the word
45、“some,” as in “some charcoal starters.”E1618 1138.5.1 Conduct carryover studies periodically, and maintainrecords that demonstrate the adequacy of laboratory proceduresto prevent carryover.8.5.2 Running a solvent blank between samples is recom-mended but is not necessary if studies demonstrate that
46、thecleaning procedure is adequate to prevent carryover.8.6 Maintain reference files of known ignitable liquids thathave been analyzed in the same manner as the questionedsamples.8.7 Chromatogram EvaluationAn adequate chromato-gram with sufficient data for comparison work is one in whichthe peaks of
47、interest are 50 to 100 % of full scale. Re-print thechromatogram, using different parameters (amplitude or pre-sentation of data) to achieve an adequately scaled chromato-gram in the targeted area of investigation.9. Data Analysis9.1 Initial data analysis consists of a visual comparison ofthe total
48、ion chromatograms to reference ignitable liquidchromatograms as described below.9.1.1 The essential requirement for making a classificationusing this procedure is the matching of the sample chromato-gram with a reference ignitable liquid chromatogram obtainedunder similar conditions, noting points o
49、f correlation or simi-larities. Make all comparisons using adequate chromatogramsas described in 8.7 and interpretation criteria described inSection 11, Interpretation of Results.9.1.2 The use of externally generated libraries of chromato-grams is not sufficient for identification of an ignitable liquid.Such libraries are intended only to give guidance for selectionof reference ignitable liquids.9.1.3 Pattern matching requires that the entire pattern usedfor comparison be displayed at the same sensitivity.9.1.3.1 To provide sufficient detail for some comparison
