1、Designation: E 1618 06e1Standard Test Method forIgnitable Liquid Residues in Extracts from Fire DebrisSamples by Gas Chromatography-Mass Spectrometry1This standard is issued under the fixed designation E 1618; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorial changes were made in November 2006.1. Scope1.1 This test method covers the
3、 identification of residues ofignitable liquids in extracts 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
4、 materials or pyrolysis products. Thistest method is also suitable for the identification of singlecompounds, simple mixtures, or non-petroleum based ignitableliquids.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This
5、 standard does not purport to address 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 Documents
6、2.1 ASTM Standards:2E 1385 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by SteamDistillationE 1386 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by SolventExtractionE 1387 Test Method for Ignitable
7、 Liquid Residues in Ex-tracts from Fire Debris Samples by Gas ChromatographyE 1388 Practice for Sampling of Headspace Vapors fromFire Debris SamplesE 1412 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Passive Headspace Concen-tration With Activated CharcoalE 1413 Pr
8、actice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Dy-namic Headspace ConcentrationE 2154 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by PassiveHeadspace Concentration with Solid Phase Microextrac-tio
9、n (SPME)3. 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 manipulating chromato-graphic and mass spectral data.3.2 Post-run data analysis generates extracted ion profiles(mass
10、chromatograms) characteristic of the chemical com-pound types commonly found in ignitable liquids.Additionally,specific chemical components (target compounds) may beidentified by their mass spectra and retention times. Semi-quantitative determination of target compounds which areidentified by mass s
11、pectra 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, alcohol, aromatic, cycloal-kane, ester, ketone and polynuclear aromatic compound types,or target compound chromatograms (TC
12、C), or combinationthereof, are evaluated by visual pattern matching againstknown reference ignitable liquids.3.2.2 Ignitable liquids may be grouped into one of sevenmajor classifications or one miscellaneous class, as describedin this test method.4. Significance and Use4.1 The identification of an i
13、gnitable liquid residue insamples from a fire scene can support the field investigatorsopinion regarding the origin, fuel load, and incendiary natureof the fire.1This test method is under the jurisdiction ofASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.0
14、1 on Criminalistics.Current edition approved June 1, 2006. Published June 2006. Originallyapproved in 1994. Last previous edition approved in 2001 as E 1618 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
15、 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.4.1.1 The identification of an ignitable liquid residue in afire scene does not necess
16、arily lead to the conclusion that a firewas incendiary in nature. Further investigation may reveal alegitimate reason for the presence of ignitable liquid residues.4.1.2 Due to the volatility of ignitable liquids and tovariations in sampling techniques, the absence of detectablequantities of ignitab
17、le 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 a fire, will form pyrolysis and combustionproducts. Extracted ion profiling and target compound identi-ficati
18、on 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. Apparatus5.1 Gas ChromatographA chromatograph capable of us-ing capillary columns and being interfaced to a mass spectro
19、m-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 capillary, bonded phase, methylsiliconeor phenylmethylsilicone column or equivalent. Any columnlength or temp
20、erature 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 operation in the range from 50 to 300C.5.2 Mass SpectrometerCapable of acquiring mass spectrafrom m/z 40 to m
21、/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, ethanol, acetone.5.2.1 SensitivityThe system must be capable of detectingeach component of the test mixture (
22、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 station, capable ofstoring time sequenced mass spectral data from sample runs.5.3.1 Data HandlingThe data system
23、 must be capable ofperforming, either through its operating system or by userprogramming, various data handling functions, including inputand storage of sample data files, generation of extracted ionprofiles, searching data files for selected compounds, andqualitative and semi-quantitative compound
24、analysis.5.3.2 Mass Spectral LibrariesThe system must be ca-pable of retrieving a specified mass spectrum from a data fileand comparing it against a library of mass spectra available tothe data system. This capability is considered an aid to theanalyst, who will use it in conjunction with chromatogr
25、aphicdata and known reference materials to identify unknowncomponents.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.5.4.2 For gas samples, a gas-tight syringe capable ofintroducing a sample size in the range of 0.5 to 5 mL.6. Che
26、micals, 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 conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety where such spec
27、ifications 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 determination.6.2 Solvent/DiluentCarbon disulfide, diethyl ether, pen-tane, or other solvent that will not interfe
28、re 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 of a heavier solvent, such as toluene or tetrachlo-roethylene, is sometimes necessary when the compounds ofinter
29、est 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 alkanes (ranging fromn-octane through n-eicosane), methylbenzene (toluene), 1,4-dimethylbenzene (p-xylene), 1-methly-2
30、-ethylbenzene (o-ethyltoluene), 1-methyl-3-ethylbenzene (m-ethyltoluene), and1,2,4-trimethlybenzene (pseudocumene). Additional com-pounds may be included at the discretion of the analyst. Thefinal test solution is prepared by diluting the above mixturesuch that the concentration of each component is
31、 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 liquids must beavailable for the various ignitable liquids represented in Table1.6.5.1 Typically, reference igni
32、table liquids are dilute 1:100in an appropriate solvent. Depending on the column capacityand injection technique, ignitable liquid solutions can be madesomewhat more concentrated to ensure detection of minorcompounds.6.5.2 Certified ignitable liquid standards are not necessary.Most reference ignitab
33、le 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 blanks and known concentrationsof either prepared test mixture or other known ignitable liquids.Optimize gas flows
34、periodically.7.2 Tune and calibrate mass spectrometer.7.2.1 Tune the mass spectrometer using perfluorotributy-lamine (PFTBA), or another appropriate calibration standard,according to the instrument manufacturers specifications,prior to use. This should be done at least every day that theinstrument i
35、s used or per manufacturers recommendations.7.2.2 Maintain tuning documentation as a portion of thequality control documentation.E161806e127.3 Cleaning the equipment.7.3.1 Change septa and clean or replace injector liners on aperiodic basis to avoid sample contamination by carryover ofresidual mater
36、ial from previous sample injections.8. Sample Handling Procedure8.1 Only samples of appropriate dilution should be analyzedon a GC/MS system.8.2 Methods for isolating ignitable liquid residues from firedebris for analysis by this test method are described inPractices E 1385, E 1386, E 1388, E 1412,
37、E 1413, andE 2154.8.3 Due to the volatility of solvents and analytes, care mustbe taken to ensure that samples do not evaporate or otherwisechange composition. Extracts in carbon disulfide may becovered with water prior to removing the extracts from theFIG. 1 Test Mixture Containing C8-C20 Normal Hy
38、drocarbons, toluene, p-xylene, o-ethyltoluene, m-ethyltoluene, and 1,2,4-trimethylbenzeneTABLE 1 Ignitable Liquid Classification SchemeAClass Light (C4-9) Medium (C8-C13) Heavy (C8C20+)Gasoline-all brands,including gasoholFresh gasoline is typically in the range C4-C12Petroleum Distillates(including
39、 De-Aromatized)Petroleum EtherSome Cigarette Lighter FluidsSome Camping FuelsSome Charcoal StartersBSome Paint ThinnersSome Dry Cleaning SolventsKeroseneDiesel FuelSome Jet FuelsSome Charcoal StartersIsoparaffinic ProductsAviation GasSome Specialty SolventsSome Charcoal StartersSome Paint ThinnersSo
40、me Copier TonersSome Commercial SpecialtySolventsAromatic ProductsSome Paint and VarnishRemoversSome Automotive Parts CleanersXylenes, Toluene-based products.Some Automotive Parts CleanersSpecialty Cleaning SolventsSome Insecticide VehiclesFuel AdditivesSome InsecticideVehiclesIndustrial CleaningSol
41、ventsNaphthenic- Paraffinic ProductsCyclohexane basedsolvents/productsSome Charcoal StartersSome Insecticide VehiclesSome Lamp OilsSome InsecticideVehiclesSome Lamp OilsIndustrial SolventsNormal-Alkanes ProductsSolventsPentaneHexaneHeptaneSome Candle OilsSome Copier TonersSome Candle OilsCarbonless
42、FormsSome Copier TonersOxygenated SolventsAlcoholsKetonesSome Lacquer ThinnersFuel AdditivesSurface Preparation SolventsSome Lacquer ThinnersSome Industrial SolventsMetal Cleaners/Gloss RemoversOthers-MiscellaneousSingle Component ProductsSome Blended ProductsSome Enamel ReducersTurpentine ProductsS
43、ome Blended ProductsSome Specialty ProductsSome Blended ProductsSome Specialty ProductsAThe products listed in 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 us
44、ed to provide more specific examples of each classification.BMany of the examples can be prefaced by the word “some,” as in “some charcoal starters.”E161806e13sample preparation hood. Alternatively, septum vials may beused for storing any solvents or extracts.8.3.1 If water is used as a sealant, exe
45、rcise care to avoid theintroduction of water onto dimethlydichlorosilane (DMCS)treated columns.8.3.2 Avoid the use of water as a sealant if the presence ofwater soluble compounds is suspected.8.4 Analyze solvent blanks at least once each day that theinstrument is used; maintain these analysis record
46、s. This willverify the purity of the solvent and potentially detect carryoveror contamination.8.5 Clean syringes thoroughly between injections to ensureno carryover.8.5.1 Conduct carryover studies, and maintain records thatdemonstrate the adequacy of laboratory procedures to preventcarryover.8.5.2 R
47、unning solvent blanks between each sample is notnecessary if studies demonstrate that the cleaning procedure isadequate 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 EvaluationA good ch
48、romatogram forcomparison work is one in which the peaks of interest are 50to 100% of full scale. Rerun samples or re-plot chromatogram,using different parameters (attenuation or sample size) toachieve a good chromatogram.8.7.1 In addition to the chromatogram described above, it issometimes necessary
49、 to produce other, off-scale plots, in orderto bring some features into view for comparison. Such off-scaleplots may be required when there are one or more componentspresent at a significantly higher concentration than the othercomponents in the sample.9. Data Analysis9.1 Initial data analysis consists of a visual comparison ofthe total 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 ignitabl
