1、Designation: E2154 15Standard Practice forSeparation and Concentration of Ignitable Liquid Residuesfrom Fire Debris Samples by Passive HeadspaceConcentration with Solid Phase Microextraction (SPME)1This standard is issued under the fixed designation E2154; the number immediately following the design
2、ation indicates the year oforiginal adoption or, in 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 practice describes the proc
3、edure for removingsmall quantities of ignitable liquid residues from samples offire debris. An adsorbent material is used to extract the residuefrom the static headspace above the sample. Then, analytes arethermally desorbed in the injection port of the gas chromato-graph (GC).1.2 This practice is b
4、est suited for screening fire debrissamples to assess relative ignitable liquid concentration and forextracting ignitable liquid from aqueous samples.1.3 This practice is suitable for extracting ignitable liquidresidues when a high level of sensitivity is required due to avery low concentration of i
5、gnitable liquid residues in thesample.1.3.1 Unlike other methods of separation and concentration,this method recovers a minimal amount of the ignitableresidues present in the evidence, leaving residues that aresuitable for subsequent resampling.1.4 Alternate separation and concentration procedures a
6、relisted in Section 2.1.5 This standard cannot replace knowledge, skill, or abilityacquired through appropriate education, training, and experi-ence and should be used in conjunction with sound profes-sional judgment.1.6 This standard does not purport to address all of thesafety concerns, if any, as
7、sociated 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 for Separation of Ignitable Liquid Resid
8、uesfrom Fire Debris Samples by Solvent ExtractionE1388 Practice for Sampling of Headspace Vapors from FireDebris SamplesE1412 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Passive Headspace Concen-tration With Activated CharcoalE1413 Practice for Separation of Ignit
9、able Liquid Residuesfrom Fire Debris Samples by Dynamic Headspace Con-centrationE1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science LaboratoryE1618 Test Method for Ignitable Liquid Residues in Extractsfrom Fire Debris Samples by Gas Chromatography-MassSpe
10、ctrometry3. Summary of Practice3.1 A fiber coated with a polydimethylsiloxane stationaryphase is exposed to the headspace of the fire debris samplecontainer to extract ignitable liquid residues. The fiber, whichis housed in a needle similar to a syringe needle, is introduceddirectly in the injection
11、 port of a gas chromatograph tothermally desorb the analytes.4. Significance and Use4.1 This practice is suited ideally for screening samples forthe presence, relative concentration, and potential class ofignitable liquid residues in fire debris.4.2 This is a very sensitive separation procedure, cap
12、able ofisolating small quantities of ignitable liquid residues from a1This practice is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved March 1, 2015. Published April 2015. Originallyap
13、proved in 2001. Last previous edition approved in 2008 as E2154 01 (2008).DOI: 10.1520/E2154-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Docume
14、nt Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1sample, that is, a 0.1 L spike of gasoline on a cellulose wipeinside of a 1-gal can is detectable.4.3 Actual recovery will vary, depending on several f
15、actors,including adsorption temperature, container size, competitionfrom the sample matrix, ignitable liquid class and relativeignitable liquid concentration.4.4 Because this separation takes place in a closedcontainer, the sample remains in approximately the samecondition in which it was submitted.
16、 Repeat and interlabora-tory analyses, therefore, may be possible. Since the extractionis nonexhaustive, the technique permits reanalysis of samples.4.5 This practice is intended for use in conjunction withother extraction techniques described in Practices E1386,E1388, E1412, and E1413.4.6 The extra
17、ct is consumed in the analysis. If a morepermanent extract is desired, one of the separation practicesdescribed in Practices E1386, E1412,orE1413 should be used.5. Apparatus5.1 Heating System, such as, an oven or heating mantle to fitthe evidence container (or a hot plate).5.2 Temperature Measuring
18、Device, such as, a thermometeror thermocouple capable of measuring temperatures in therange of 40 to 110C.5.3 SPME Apparatus, such as, a solid phase microextractionfiber holder.5.4 SPME FiberSeveral polymer coatings can be used toextract volatiles such as ignitable liquid residues. A100 mpolydimethy
19、lsiloxane (PDMS) coating has been shown toperform well for most C10-C25compounds while a 85 mPolyacrylate (PA) and a combined 75 m Carboxen/PDMS hasbeen shown to perform well for C1-C10compounds (1).35.5 Punch.5.6 Rubber Sleeve Septum.6. Sample Preparation/Analysis Procedure6.1 Observe the appropria
20、te procedures for handling anddocumentation of all submitted samples as described in Prac-tice E1492.6.1.1 Open and examine the fire debris sample to determinethat it is consistent with its description.6.1.1.1 Resolve any discrepancies between the submittingagents description of the evidence and the
21、 analysts observa-tion with the submitting agent prior to the completion of thereport.6.2 Verify that the fiber is free of ignitable residue compo-nents and other contaminates by introducing the fiber into theGC under the injector desorption and chromatographic condi-tions for ignitable residue anal
22、ysis. This fiber residue “blank”always should be evaluated before residue sampling whenperforming a manual injection and desorption.6.2.1 Perform batch runs of fiber blanks in advance whennecessary for autosampler apparatus.6.3 If the sample container has a metal lid, make a hole inthe lid and insta
23、ll a rubber sleeve septum in the opening.6.4 Heat the container until the sample reaches the desiredtemperature (approximately 20-30 min, but longer equilibra-tion times may be needed depending on the heating method orthe amount and type of matrix present in the can, or both).6.4.1 Temperatures lowe
24、r than 60C may be insufficient tovolatilize compounds above C16.6.4.2 Temperatures above 80C may result in a significantdiscrimination against high volatility compounds when the 100m PDMS fiber is used.6.5 Remove the container from the heating apparatus.6.6 Immediately puncture the rubber sleeve sep
25、tum orplastic evidence bag with the needle of the SPME apparatus.6.7 Expose the SPME fiber to the headspace of the containerfor the desired sampling duration.6.7.1 The optimum exposure time for maximum sensitivitywill depend on the temperature and the concentration andcomposition of the volatile com
26、pound present in the sampleheadspace.6.7.2 Exposure times for routine screening of samplestypically are in the range of 5-15 min.6.7.3 Residue extracts that provide off-scale or poorlyresolved chromatographic responses should be resampled atlower temperatures or shorter exposure times.6.8 Secure the
27、 fiber in the needle by withdrawing it into theSPME apparatus. Remove the apparatus from the samplecontainer.6.8.1 Rubber sleeve septa are self-sealing. Puncture holes inevidence bags should be sealed after sampling.6.9 Desorb the fiber for approximately 1.5 to 4 min at aminimum of 200C and 260C and
28、 analyze the adsorbate byexposing the fiber in the injection port of a gas chromatograph.Analysis is performed as described in Test Method E1618.6.9.1 Some instruments can desorb fibers using an autosam-pler apparatus. The acceptability of the autosampler parametersshall be verified using known igni
29、table liquids and fiber blankswithin a sequence.6.10 A blank shall be run before each sample to ensure thatthe fiber is completely desorbed and free of contaminants.6.10.1 A blank is run by exposing and analyzing the fiber inthe gas chromatograph under normal operating conditions.6.11 Record the ads
30、orption parameters including the expo-sure time and temperature in the analytical case notes.7. Blanks and Standards7.1 Analysis of a fiber blank (6.2) is required immediatelybefore each manual sample extraction and batch analysis offiber blanks prior to sample extractions when using autosam-pler ap
31、paratus.7.1.1 If an internal standard is routinely used, include theinternal standard in the blank run by placing the internal3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.E2154 152standard in an empty container and exposing the SPME fiber asdescribed
32、in Section 6.7.2 Periodically check the adsorption efficiency of the fiberby running this procedure on a sample containing a knownvolume of an ignitable liquid standard.7.3 An ignitable liquid standards library should be main-tained with neat and evaporated commonly ignitable liquidsrecovered from s
33、ample containers by this technique at variousconcentrations.8. Keywords8.1 fire debris samples; passive headspace concentration;solid phase microextraction (SPME)REFERENCES(1) Ren, Q.L., and Bertsch, W.A., “A Comprehensive Sample PreparationScheme for Accelerants in Suspect Arson Cases,” Journal of
34、ForensicScience, JFSCA, Vol 44, No. 3, May 1999, pp. 504515.(2) Furton, K.G., Almirall, J.R., and Bruna, J., “A Simple, Inexpensive,Rapid, Sensitive and Solventless Technique for the Analysis ofAccelerants in Fire Debris Based on SPME,” Journal of HighResolution Chromatography, Vol 18, October 1995,
35、 pp. 15.(3) Furton, K.G., Almirall, J.R., and Bruna, J., “A Novel Method for theAnalysis of Gasoline from Fire Debris Using Headspace Solid PhaseMicroextraction,” Journal of Forensic Science, JFSCA, Vol 41, No. 1,January 1996, pp. 1222.(4) Almirall, J.R., Bruna, J., and Furton, K.G., “The Recovery o
36、fAccelerants in Aqueous Samples from Fire Debris Using Solid PhaseMicroextraction (SPME),” Science and Justice, Journal of the Foren-sic Science Society, Vol 36, No. 4, 1996, pp. 283287.(5) Almirall, J.R., Wang, J., Lothridge, K., and Furton, K.G., “TheDetection and Analysis of Flammable or Combusti
37、ble Liquid Resi-dues on Human Skin,” Journal of Forensic Science, JFSCA, Vol 45,No. 2, March 2000, pp. 453461.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised
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