ASTM E2154-2001 Standard Practice for Separation and Concentration of Ignitable Liquid Residues from Fire Debris Samples by Passive Headspace Concentration with Solid Phase Microex.pdf

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1、Designation: E 2154 01Standard 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 E 2154; the number immediately following the desi

2、gnation 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes the p

3、rocedure 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 i

4、s best 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 o

5、f ignitable 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 procedure

6、s arelisted in Section 2.1.5 This 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 pri

7、or to use.2. Referenced Documents2.1 ASTM Standards:E 1385 Practice for Separation and Concentration of Flam-mable or Combustible Liquid Residues from Fire DebrisSamples by Steam Distillation2E 1386 Practice for Separation and Concentration of Flam-mable or Combustible Liquid Residues from Fire Debr

8、isSamples by Solvent Extraction2E 1387 Test Method for Flammable or Combustible LiquidResidues in Extracts from Samples of Fire Debris by GasChromatography2E 1388 Practice for Sampling Headspace Vapors from FireDebris Samples2E 1412 Practice for Separation and Concentration of Flam-mable or Combusti

9、ble Liquid Residues from Fire DebrisSamples by Passive Headspace Concentration with Acti-vated Charcoal2E 1413 Practice for Separation and Concentration of Flam-mable or Combustible Liquid Residues from Fire DebrisSamples by Dynamic Headspace Concentration2E 1459 Guide for Physical Evidence Labeling

10、 and RelatedDocumentation2E 1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science Laboratory2E 1618 Guide for Ignitable Liquid Residues in Extractsfrom Fire Debris Samples by Gas Chromatography-MassSpectrometry23. Summary of Practice3.1 A fiber coated with a

11、 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 port of a gas chromatograph tothermally desorb the anal

12、ytes.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, capable ofisolating small quantities of ignitable liquid re

13、sidues from asample, 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 factors,including adsorption temperature, container size, competitionfrom the sample matrix, ignitable liquid class and relativeignitable

14、 liquid concentration.4.4 Because this separation takes place in a closed con-tainer, the sample remains in approximately the same conditionin which it was submitted. Repeat and interlaboratory analyses,therefore, may be possible. Since the extraction is nonexhaus-tive, the technique permits reanaly

15、sis of samples.1This 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 Sept 10, 2001. Published December 2001.2Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM Intern

16、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.5 This practice is intended for use in conjunction withother extraction techniques described in Practices E 1385,E 1386, E 1388, E 1412, and E 1413.4.6 The extract is consumed in the analysis. If a moreper

17、manent extract is desired, one of the separation practicesdescribed in Practices E 1385, E 1386, E 1412, or E 1413should 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 Device, such as, a thermometeror

18、 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. A 100 mpolydimethylsiloxane (PDMS) coating has be

19、en 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 (5).5.5 Punch.5.6 Rubber Sleeve Septum.6. Sample Preparation/Analysis Procedure6.1 Observe the appropriate procedures for handling anddo

20、cumentation of all submitted samples as described in Prac-tice E 1492.6.1.1 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 analysts observa-tion with the

21、 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 analysis. This fiber residue “blank

22、”always should be evaluated before residue sampling.6.3 If the sample container has a metal lid, make a hole inthe lid and install 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 ma

23、y be needed depending on the heating method orthe amount and type of matrix present in the can, or both).6.4.1 Temperatures lower than 60C may be insufficient tovolatilize compounds above C16.6.4.2 Temperatures above 80C may result in a significantdiscrimination against high volatility compounds whe

24、n the 100m PDMS fiber is used.6.5 Remove the container from the heating apparatus.6.6 Immediately puncture the rubber sleeve septum 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 opti

25、mum exposure time for maximum sensitivitywill depend on the temperature and the concentration andcomposition of the volatile compound 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-sca

26、le or poorlyresolved chromatographic responses should be resampled atlower temperatures or shorter exposure times.6.8 Secure the 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 inev

27、idence 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 analyze the adsorbate byexposing the fiber in the injection port of a gas chromatograph.Analysis is performed as described in Test Method E 1387 orGuide E 1618.6.10 A blan

28、k 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 adsorption parameters including the expo-sure time and tempera

29、ture in the analytical case notes.7. Blanks and Standards7.1 Analysis of a fiber blank (6.2) is required immediatelybefore each sample extraction.7.1.1 If an internal standard is routinely used, include theinternal standard in the blank run by placing the internalstandard in an empty container and e

30、xposing the SPME fiber asdescribed 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 commonl

31、y ignitable liquidsrecovered from sample containers by this technique at variousconcentrations.8. Keywords8.1 fire debris samples; passive headspace concentration;solid phase microextraction (SPME)E 21542REFERENCES(1) Furton, K.G., Almirall, J.R., and Bruna, J., “A Simple, Inexpensive,Rapid, Sensiti

32、ve and Solventless Technique for the Analysis ofAccelerants in Fire Debris Based on SPME,” J. of High ResolutionChromatography, Vol 18, October 1995, pp. 1-5.(2) Furton, K.G., Almirall, J.R., and Bruna, J., “A Novel Method for theAnalysis of Gasoline from Fire Debris Using Headspace Solid PhaseMicro

33、extraction,” J. of Forensic Science, JFSCA, Vol 41, No. 1,January 1996, pp. 12-22.(3) Almirall, J.R., Bruna, J., and Furton, K.G., “The Recovery ofAccelerants in Aqueous Samples from Fire Debris Using Solid PhaseMicroextraction (SPME),” Science and Justice, J. of the ForensicScience Society, Vol 36,

34、 No. 4, 1996, pp. 283-287.(4) Almirall, J.R., Wang, J., Lothridge, K., and Furton, K.G., “TheDetection and Analysis of Flammable or Combustible Liquid Residueson Human Skin,” J. of Forensic Science, JFSCA, Vol 45, No. 2, March2000, pp. 453-461.(5) Ren, Q.L., and Bertsch, W.A., “A Comprehensive Sampl

35、e PreparationScheme for Accelerants in Suspect Arson Cases,” J. of ForensicScience, JFSCA, Vol 44, No. 3, May 1999, pp. 504-515.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

36、 expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not r

37、evised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you

38、 may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E 21543