ASTM E2154-2001(2008) Standard Practice for Separation and Concentration of Ignitable Liquid Residues from Fire Debris Samples by Passive Headspace Concentration with Solid Phase M.pdf

1、Designation: E 2154 01 (Reapproved 2008)Standard 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

2、following the designation 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 practi

3、ce describes the procedure 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

4、.2 This practice is 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 l

5、ow concentration of 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 conce

6、ntration procedures 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 regulato

7、ry limitations prior to use.2. Referenced Documents2.1 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 b

8、y SolventExtractionE 1387 Test Method for Ignitable 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 Headsp

9、ace Concen-tration With Activated CharcoalE 1413 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Dy-namic Headspace ConcentrationE 1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science LaboratoryE 1618 Test

10、 Method for Ignitable Liquid Residues in Ex-tracts from Fire Debris Samples by Gas Chromatography-Mass Spectrometry3. 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.

11、 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 analytes.4. Significance and Use4.1 This practice is suited ideally for screening samples forthe presence, relative concentration, and potenti

12、al class ofignitable liquid residues in fire debris.4.2 This is a very sensitive separation procedure, capable ofisolating small quantities of ignitable liquid residues 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 va

13、ry, depending on several factors,including adsorption temperature, container size, competitionfrom the sample matrix, ignitable liquid class and relativeignitable liquid concentration.1This practice is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility

14、of Subcommittee E30.01 on Criminalistics.Current edition approved Feb. 1, 2008. PublishedApril 2008 Originally approvedin 2001. Last previous edition approved in 2001 as E 215401.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org.

15、 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.4.4 Because this separation takes place in a closed con-tainer, the

16、 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 reanalysis of samples.4.5 This practice is intended for use in conjunction withother extraction

17、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 morepermanent extract is desired, one of the separation practicesdescribed in Practices E 1385, E 1386, E 1412,orE 1413should be used.5. Apparatus5.1 Heating System, such as,

18、 an oven or heating mantle to fitthe evidence container (or a hot plate).5.2 Temperature Measuring 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 po

19、lymer coatings can be used toextract volatiles such as ignitable liquid residues. A 100 mpolydimethylsiloxane (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 (5).5

20、.5 Punch.5.6 Rubber Sleeve Septum.6. Sample Preparation/Analysis Procedure6.1 Observe the appropriate procedures for handling anddocumentation 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 descriptio

21、n.6.1.1.1 Resolve any discrepancies between the submittingagents description of the evidence and the 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

22、 into theGC under the injector desorption and chromatographic condi-tions for ignitable residue analysis. This fiber residue “blank”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.

23、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 lower than 60C may be insufficient tovolatili

24、ze 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 septum orplastic evidence bag with the needl

25、e 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 compound present in the sampleheadspace.6.7.

26、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 fiber in the needle by withdrawing it in

27、to 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 analyze the adsorbate byexposing the fib

28、er in the injection port of a gas chromatograph.Analysis is performed as described in Test Method E 1387 orGuide E 1618.6.10 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

29、 gas chromatograph under normal operating conditions.6.11 Record the adsorption 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 sample extraction.7.1.1 If an internal st

30、andard is routinely used, include theinternal standard in the blank run by placing the internalstandard in an empty container and exposing 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 knownvolu

31、me of an ignitable liquid standard.7.3 An ignitable liquid standards library should be main-tained with neat and evaporated commonly ignitable liquidsrecovered from sample containers by this technique at variousconcentrations.8. Keywords8.1 fire debris samples; passive headspace concentration;solid

32、phase microextraction (SPME)E 2154 01 (2008)2REFERENCES(1) 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,” J. of High ResolutionChromatography, Vol 18, October 1995, pp. 1-5.(

33、2) Furton, K.G., Almirall, J.R., and Bruna, J., “A Novel Method for theAnalysis of Gasoline from Fire Debris Using Headspace Solid PhaseMicroextraction,” 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

34、in Aqueous Samples from Fire Debris Using Solid PhaseMicroextraction (SPME),” Science and Justice, J. of the ForensicScience Society, Vol 36, No. 4, 1996, pp. 283-287.(4) Almirall, J.R., Wang, J., Lothridge, K., and Furton, K.G., “TheDetection andAnalysis of Flammable or Combustible Liquid Residueso

35、n 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 Sample PreparationScheme for Accelerants in Suspect Arson Cases,” J. of ForensicScience, JFSCA, Vol 44, No. 3, May 1999, pp. 504-515.ASTM International takes no posi

36、tion respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibili

37、ty.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to AST

38、M International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you 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

39、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 2154 01 (2008)3