ASTM E1412-2007 Standard Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Passive Headspace Concentration With Activated Charcoal《用被动顶空活性碳浓缩法从火烧瓦砾样品.pdf

1、Designation: E 1412 07Standard Practice forSeparation of Ignitable Liquid Residues from Fire DebrisSamples by Passive Headspace Concentration WithActivated Charcoal1This standard is issued under the fixed designation E 1412; the number immediately following the designation indicates the year oforigi

2、nal 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 covers the procedure for removing smallquantities

3、 of ignitable liquid residue from samples of fire debrisusing an adsorbent material to extract the residue from thestatic headspace above the sample, then eluting the adsorbentwith a solvent.1.2 While this practice is suitable for successfully extractingignitable liquid residues over the entire rang

4、e of concentration,the headspace concentration methods are best used when a highlevel of sensitivity is required due to a very low concentrationof ignitable liquid residues in the sample.1.2.1 Unlike other methods of separation and concentration,this practice is essentially nondestructive.1.3 Altern

5、ate separation and concentration procedures arelisted in the referenced documents. (see Practices E 1385,E 1386, E 1388, and E 1413).1.4 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 estab

6、lish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE 752 Practice for Safety and Health Requirements Relatingto Occupational Exposure to Carbon Disulfid

7、eE 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 Liquid Residues in

8、 Ex-tracts from Samples of Fire Debris by Gas Chromatogra-phyE 1388 Practice for Sampling of Headspace Vapors fromFire Debris SamplesE 1413 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Dy-namic Headspace ConcentrationE 1459 Guide for Physical Ev

9、idence Labeling and RelatedDocumentationE 1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science LaboratoryE 1618 Guide for Ignitable Liquid Residues in Extractsfrom Fire Debris Samples by Gas Chromatography-MassSpectrometry3. Summary of Practice3.1 Charcoal

10、in some form of an adsorption package isplaced in the sample container to adsorb ignitable liquidresidues. The container may be heated or left at ambienttemperature. The charcoal is removed and eluted with asuitable elution solvent as listed in Section 6.3.4. Significance and Use4.1 This practice is

11、 useful for preparing extracts from firedebris for later analysis by gas chromatography, GC/MS, orGC/IR.4.2 This is a very sensitive separation procedure, capable ofisolating quantities smaller than110 L of ignitable liquidresidue from a sample.5. Apparatus5.1 Heating SystemAn oven, or a heating man

12、tle to fit theevidence container (or a hot plate).5.1.1 An oven is recommended to achieve a constanttemperature throughout the system.1This practice is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current e

13、dition approved April 15, 2007. Published June 2007. Originallyapproved in 1991. Last previous edition approved in 2005 as E 1412 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor

14、mation, 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.5.2 Temperature Measuring DeviceA thermometer orthermocouple capable of measuring temperatures in the rangeof 40

15、to 150C.5.3 Adsorption Package.5.3.1 Commercial charcoal adsorption packages are avail-able from several companies. These packages, in the form ofpolymer strips or small charcoal canisters or “C bags,” are usedto adsorp organic vapors.5.3.1.1 The minimum recommended polymer strip size is 10mm by 10

16、mm, or 100 mm2.5.3.2 Non-Commercial Adsorption Packages.5.3.2.1 C-BagsPrepare C-bags by encapsulating 0.2 g ofactivated charcoal within a folded sheet of high strength, lightweight, high porosity tissue paper, such as that commonly usedfor making tea bags.35.3.3 Storage of Adsorption Packages To pre

17、vent con-tamination, store all adsorption packages away from anysources of organic vapors prior to and after use for sampling.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the s

18、pecifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.4Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.

19、6.1.1 Purity of WaterUnless otherwise indicated, refer-ences to water shall be understood to mean reagent water asdefined by Type IV of Specification D 1193.6.2 C-Bags:6.2.1 4 by 5 in. (approximate) high strength, light weight,high porosity filter paper.6.2.2 Activated Charcoal.6.3 Elution SolventSu

20、itable elution solvents are carbondisulfide, npentane, or diethyl ether. Use of a heavier solvent,such as toluene or tetrachloroethylene, is sometimes necessarywhen the compounds of interest have low molecular weights.6.3.1 Check solvent purity by evaporating to at least twicethe extent used in the

21、analysis and analyzing the evaporatedsolvent in accordance with Test Method E 1387 or Test MethodE 1618.6.3.2 Read and follow the safety precautions described inPractice E 752.6.3.3 Diethyl Ether, GC or HPLC grade.6.3.3.1 Pentane and diethyl ether produce relatively largesignals when passing through

22、 a flame ionization detector,possibly obscuring the signal from lighter hydrocarbons.7. Sample Preparation/Adsorption Procedure7.1 Observe the appropriate procedures for handling anddocumentation of all submitted samples as described in Prac-tice E 1492.7.1.1 Open and examine the fire debris sample

23、in order todetermine that it is consistent with its description.7.1.1.1 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.7.2 Remove an adsorbent package from its sealed pack

24、agingand place it in the evidence container, then reseal the container.7.3 Heat the container to a temperature of 50 to 80C, for 2to 24 h. The longer times or higher temperatures, or both, arerequired for the adsorption of higher boiling point compoundsor for the adsorption of very small quantities

25、of volatilehydrocarbons. The adsorption temperature and duration mayvary based on the sample.5,37.3.1 When other evidentiary considerations arise (such asdocument or latent print examinations) it may be appropriate toconduct the adsorption at ambient temperature (approximately20C) for extended perio

26、ds (24 h or longer) to minimizedamage.7.3.2 Room temperature adsorption may also be appropriateto detect low molecular weight compounds.3Dietz, W. R., “Improved Charcoal Packaging for Accelerant Recovery byPassive Diffusion,” Journal of Forensic Sciences , Vol 35, 1991, pp. 111121. (Unk)4Reagent Che

27、micals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand Natio

28、nal Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.5Newman, R, et.al., “The Use of Activated Charcoal Strips for Fire DebrisExtractions by Passive Diffusion. Part 1: The Effects of Time, Temperature, StripSize and Sample Concentration,” Journal of Forensic Sciences, Vol 41, 199

29、6, pp.351-370.E1412072MR RANKIN-THE STANDARD ALREADY HAD A 7.3.1 AND 7.3.2 (I RENUMBERED AS 7.3.3 AND 7.3.4. IWASNT SURE IF THEY WERE TO BE DELETED OR RENUMBERED. PLEASE ADVISE7.3.3 The optimum adsorption time for maximum sensitiv-ity will depend on the adsorption package and temperatureselected. Te

30、mperatures lower than 60C may be insufficient tovolatilize compounds heavier than C16.7.3.4 Temperatures in excess of 80C may result in dispro-portionate recovery of higher molecular weight compoundswith the displacement of lower molecular weight compounds.7.3.5 The optimum adsorption time for repre

31、sentative sam-pling or maximum sensitivity, or both, will depend on theadsorption package, the adsorption temperature, and the ignit-able liquid composition and concentration.7.3.5.1 Adsorption times for routine screening of samplesare typically in the range of 8 to 24 h.7.3.5.2 Data that appears ov

32、erloaded or excessively dis-placed may be corrected by resampling at ambient tempera-tures, or with shortened adsorption times (1 to 4 h).7.4 0.1 L or 0.5 L of an internal standard may be added tothe sample in order to check on the efficiency of the procedure.Internal standards are typically prepare

33、d using a single com-pound that is easily identified (such as 3-phenyltoluene ordiphenylmethane) dissolved in the eluting solvent.7.5 Document the adsorption parameters including the typeand amount of adsorbent used, adsorption temperature andadsorption time.8. Elution Procedure8.1 Remove the adsorp

34、tion package from the evidencecontainer. If it is not to be eluted immediately, store theadsorption package in a clean, vapor-tight container.8.2 Code or label an appropriately sized vial or test tubewith the case number, sample number, date, separation method,and analysts initials.8.2.1 Follow the

35、evidence documentation and handlingprocedures described in Guide E 1459 and Practice E 1492.8.3 Place the adsorption substrate in a properly labeledcontainer and rinse with a minimal amount of eluting solventrequired for instrumental analysis (typically 50 to 1000 L).8.4 Document the type and volume

36、 of solvent used to elutethe adsorbent.9. Sealing9.1 A septum seal vial may be used for collecting andsealing the extract.9.1.1 A test tube containing CS2may be sealed by theaddition of water, which will float on top of the CS2and reduceits evaporation.10. Extract and Adsorbent Storage10.1 After ana

37、lysis, the eluate may be placed back in thevial or test tube with the adsorbent package. Hydrocarbonspresent in the eluate will be readsorbed onto the charcoal.10.2 Alternately, a portion of the adsorbed charcoal may beseparated and stored prior to elution and analysis of theremaining adsorbent.11.

38、Blanks and Standards11.1 Run frequent blanks on each lot of adsorbent packages.11.1.1 Prepare a blank by placing an adsorbent package intoa clean dry evidence container and running the adsorptionprocedure as described in Section 7. Elute the adsorptionpackage according to Section 8, and analyze the

39、extractaccording to Test Method E 1387 or Guide E 1618.11.1.1.1 If an internal standard is routinely used, include aninternal standard in the blank.11.2 When necessary, charcoal may be activated andcleaned by heating in a 400C oven for 4 h, then cooling in adessicator.11.3 Periodically check the ads

40、orption efficiency by runningthis procedure on a sample containing a known volume ofstandard ignitable liquid.12. Keywords12.1 fire debris samples; passive headspace concentrationASTM International takes no position respecting the validity of any patent rights asserted in connection with any item me

41、ntionedin 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 responsibility.This standard is subject to revision at any time by the responsible technical committe

42、e 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 ASTM International Headquarters. Your comments will receive careful consideration at a meeti

43、ng 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 shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO

44、 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).E1412073