ASTM E1412-2012 Standard Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Passive Headspace Concentration With Activated Charcoal《通过用活性炭的被动顶部空间浓缩法从火.pdf

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1、Designation:E141207 Designation: E1412 12Standard Practice forSeparation of Ignitable Liquid Residues from Fire DebrisSamples by Passive Headspace Concentration WithActivated Charcoal1This standard is issued under the fixed designation E1412; the number immediately following the designation indicate

2、s 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 coversdescribes the procedure fo

3、r removing separation of small quantities of ignitable liquid residues fromsamples of fire debris using an adsorbent material to extract the residue from the static headspace above the sample, then elutingthe adsorbent with a solvent.1.2 While this practice is suitable for successfully extracting ig

4、nitable liquid residues over the entire range of concentration, theheadspace concentration methods are best used when a high level of sensitivity is required due to a very low concentration ofignitable liquid residues in the sample.1.2.1 Unlike other methods of separation and concentration, this pra

5、ctice is essentially nondestructive.1.3 Alternate separation and concentration procedures are listed in the referenced documents (see Practices E1385, E1386,E1388, and , E1413, and E2154).1.41.4 This practice does not replace knowledge, skill, ability, experience, education, or training and should b

6、e used in conjunctionwith professional judgment.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsib

7、ilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193Specification for Reagent WaterE752Practice for Safety and Health Requirements Relating to Occu

8、pational Exposure to Carbon DisulfideE1385Practice for Separation and Concentration of Ignitable Liquid Residues from Fire Debris Samples by Steam DistillationE1386 Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Solvent Extraction E1387Test Methodfor IgnitableLiquid

9、 Resi-dues in Ex-tracts fromFire DebrisSamples byGas Chroma-tographyE1388 Practice for Sampling of Headspace Vapors from Fire Debris SamplesE1413 Practice for Separation and Concentration of Ignitable Liquid Residues from Fire Debris Samples by DynamicHeadspace ConcentrationE1459 Guide for Physical

10、Evidence Labeling and Related DocumentationE1492 Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science LaboratoryE1618 Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatography-Mass1This practice is under the jurisdicti

11、on of ASTM Committee E30 on Forensic Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approvedApril 15, 2007. Published June 2007. Originally approved in 1991. Last previous edition approved in 2005 as E141205. DOI: 10.1520/E1412-07.Current edition a

12、pproved June 1, 2012. Published July 2012. Originally approved in 1991. Last previous edition approved in 2007 as E1412 07. DOI: 10.1520/E1412-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standar

13、dsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible t

14、o adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con

15、shohocken, PA 19428-2959, United States.Spectrometry Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatography-MassSpectrometryE2154 Practice for Separation and Concentration of Ignitable Liquid Residues from Fire Debris Samples by Passive HeadspaceConcentr

16、ation with Solid Phase Microextraction (SPME)E2451 Practice for Preserving Ignitable Liquids and Ignitable Liquid Residue Extracts from Fire Debris Samples3. Summary of Practice3.1 Charcoal in some form of an adsorption package is placed in the sample container to adsorb ignitable liquid residues. T

17、hecontainer may be heated or left at ambient temperature. The charcoal is removed and eluted with a suitable elution solvent as listedin 6.3.4. Significance and Use4.1 This practice is useful for preparing extracts from fire debris for later analysis by gas chromatography, GC/MS, or GC/IR.chromatogr

18、aphy mass spectrometry.4.2 This is a very sensitive separation procedure, capable of isolating quantities smaller than110 L of ignitable liquid residuefrom a sample.5. Apparatus5.1 Heating SystemAn oven, or a heating mantle to fit the evidence container (or a hot plate).5.1.1 An oven is recommended

19、to achieve a constant temperature throughout the system.5.2 Temperature Measuring DeviceA thermometer or thermocouple capable of measuring temperatures in the range of 40 to150C.5.3 Adsorption Package.5.3.1 Commercial charcoal adsorption packages are available from several companies. These packages,

20、 in the form of polymerstrips or small charcoal canisters or “C bags,” are used to adsorpadsorb organic vapors.5.3.1.1 The minimum recommended polymer strip size is 10 mm by 10 mm, or 100 mm2.5.3.2 Non-Commercial Adsorption Packages.5.3.2.1 C-BagsPrepare C-bags by encapsulating 0.2 g of activated ch

21、arcoal within a folded sheet of high strength, lightweight, high porosity tissue paper, such as that commonly used for making tea bags.35.3.3 Storage of Adsorption PackagesTo prevent contamination, store all adsorption packages away from any sources oforganic vapors prior to and after use for sampli

22、ng.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are availa

23、ble.4Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determination.6.1.1Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water as define

24、d byType IV of Specification D1193.6.2 Adsorption Package:6.2.1 C-Bags:6.2.14 by 5 in. (approximate) high strength, light weight, high porosity filter paper.6.2.2Activated Charcoal6.2.1.1 4 by 5 in. (approximate) high strength, light weight, high porosity filter paper.6.2.1.2 Activated charcoal.6.2.

25、2 Commercial charcoal adsorption package.6.2.3 Check charcoal media purity by, at a minimum, desorbing a representative unit using the same elution solvent as will beused for questioned samples and analyzing in accordance with Test Method E1618.6.3 Elution SolventSuitable elution solvents are carbon

26、 disulfide, n pentane, or diethyl ether. Use of a heavier solvent, suchas toluene or tetrachloroethylene, is sometimes necessary when the compounds of interest have low molecular weights.6.3.1 Check solvent purity by evaporating to at least twice the extent used in the analysis and analyzing the eva

27、porated solventin accordance with Test Method E1387 or Test Method E1618.6.3.2Read and follow the safety precautions described in Practice E752.3Dietz, W. R., “Improved Charcoal Packaging for Accelerant Recovery by Passive Diffusion,” Journal of Forensic Sciences, Vol 35, 1991, pp. 111121 (Unk).4Die

28、tz, W. R., “Improved Charcoal Packaging for Accelerant Recovery by Passive Diffusion,” Journal of Forensic Sciences, Vol 35, 1991, pp. 111121 (Unk).4Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not

29、listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.E1412 1226.3.3Diethyl Ether, GC or HPLC grade.6.3.3.1Pentane and

30、diethyl ether produce relatively large signals when passing through a flame ionization detector, possiblyobscuring the signal from lighter hydrocarbons.6.3.2 Read and follow the safety precautions described in the MSDS of the extraction solvent that is used.7. Sample Preparation/Adsorption Procedure

31、7.1 Observe the appropriate procedures for handling and documentation of all submitted samples as described in PracticeE1492.7.1.1 Open and examine the fire debris sample in order to determine that it is consistent with its description.7.1.1.1 Resolve any discrepancies between the submitting agentsa

32、gencys description of the evidence and the analystsanalystsobservation with the submitting agent prior to the completion of the report.7.2 Remove an adsorbent package from its sealed packaging and place it in the evidence container, then reseal the container.7.3 Heat the container to a temperature o

33、f 50 to 80C, for 2 to 24 h. The longer times or higher temperatures, or both, arerequired for the adsorption of higher boiling point compounds or for the adsorption of very small quantities of volatilehydrocarbons. The adsorption temperature and duration may vary based on the sample.5, 37.3.1 When o

34、ther evidentiary considerations arise (such as document or latent print examinations) it may be appropriate toconduct the adsorption at ambient temperature (approximately 20C) for extended periods (24 h or longer) to minimize damage.7.3.2 Room temperature adsorption may also be appropriate to detect

35、 low molecular weight compounds.7.3.3 The optimum adsorption time for maximum sensitivity will depend on the adsorption package and temperature selected.Temperatures lower than 60C may be insufficient to volatilize compounds heavier than C16.7.3.4 Temperatures in excess of 80C may result in dispropo

36、rtionate recovery of higher molecular weight compounds with thedisplacement of lower molecular weight compounds.7.3.5 The optimum adsorption time for representative sampling or maximum sensitivity, or both, will depend on the adsorptionpackage, the adsorption temperature, and the ignitable liquid co

37、mposition and concentration.7.3.5.1 Adsorption times for routine screening of samples are typically in the range of 8 to 24 h.7.3.5.2 Data that appears overloaded or excessively displaced may be corrected by resampling at ambient temperatures, or withshortened adsorption times (1 to 4 h).7.4 0.1 L o

38、r 0.5 L of an internal standard may be added to the sample in order to check on the efficiency of the procedure.Internal standards are typically prepared using a single compound that is easily identified (such as 3-phenyltoluene ordiphenylmethane) dissolved in the eluting solvent.7.5 Document the ad

39、sorption parameters including the type and amount of adsorbent used, adsorption temperature andadsorption time.8. Elution Procedure8.1 Remove the adsorption package from the evidence container. If it is not to be eluted immediately, store the adsorptionpackage in a clean, vapor-tight container.8.2Co

40、de or label an appropriately sized vial or test tube with the case number, sample number, date, separation method, andanalysts initials.8.2.1Follow the evidence documentation and handling procedures described in Guide8.2 Follow the evidence documentation and handling procedures described in Guide E1

41、459 and Practice E1492.8.3 Place the adsorption substrate in a properly labeled container and rinse with a minimal amount of eluting solvent requiredfor instrumental analysis (typically 50 to 1000 L).8.4 Document the type and volume of solvent used to elute the adsorbent.9. Sealing9.1A septum seal v

42、ial may be used for collecting and sealing the extract.9.1.1A test tube containing CS2may be sealed by the addition of water, which will float on top of the CS2and reduce itsevaporation.9.1 A septum seal or screw cap glass vial may be used for collecting and sealing the extract for analysis.10. Extr

43、act and Adsorbent Storage10.1After analysis, the eluate may be placed back in the vial or test tube with the adsorbent package. Hydrocarbons present inthe eluate will be readsorbed onto the charcoal.5Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington,

44、DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.5Newman, R, et

45、 al., “The Use of Activated Charcoal Strips for Fire Debris Extractions by Passive Diffusion. Part 1: The Effects of Time, Temperature, Strip Size andSample Concentration,” Journal of Forensic Sciences, Vol 41, 1996, pp. 351370.E1412 12310.2Alternately, a portion of the adsorbed charcoal may be sepa

46、rated and stored prior to elution and analysis of the remainingadsorbent.10.1 Refer to Practice E2451 for short term and long term storage of ignitable liquid extracts.11. Blanks and Standards11.1 Run frequent blanks on each lot of adsorbent packages.11.1.1Prepare a blank by placing an adsorbent pac

47、kage into a clean dry evidence container and running the adsorption procedureas described in Section11.1.1 Analyze an absorbent package blank by eluting the adsorbent with 50 to 1000 L of solvent and analyze according toTest Method E1618.11.1.2 Prepare a system blank by placing an adsorbent package

48、into a clean dry evidence container and running the adsorbentprocedure as described in Section 7. Elute the adsorption package according to Section 8, and analyze the extract according to TestMethod E1387 or Guide E1618.11.1.12.1 If an internal standard is routinely used, include an internal standar

49、d in the blank.11.2 When necessary, charcoal may be activated and cleaned by heating in a 400C oven for 4 h, then cooling in a dessiccator.11.3 Periodically check the adsorption efficiency by running this procedure on a sample containing a known volume of standardignitable 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 mentionedin this standard. Users of this standard are expressly advised that determinati