1、Designation: E 2451 08Standard Practice forPreserving Ignitable Liquids and Ignitable Liquid ResidueExtracts from Fire Debris Samples1This standard is issued under the fixed designation E 2451; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 procedures for preserving resi-dues of ignitable liquids in extracts o
3、btained from fire debrissamples and questioned ignitable liquid samples. Extractionprocedures are described in the Referenced Documents.1.2 This practice does not attempt to address all the issuesregarding the short-term or long-term storage of ignitableliquid samples and ignitable liquid extracts f
4、rom fire debrissamples. The changes that may occur under various storageconditions have not been fully documented.1.3 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 s
5、afety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 1386 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by SolventExtractionE 1387 Test Method for Ignitable L
6、iquid 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 Headspace Concen-tration With Activated CharcoalE 1413 Prac
7、tice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Dy-namic Headspace ConcentrationE 1459 Guide for Physical Evidence Labeling and RelatedDocumentationE 1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science Labora
8、toryE 1618 Test Method for Ignitable Liquid Residues in Ex-tracts from Fire Debris Samples by Gas Chromatography-Mass SpectrometryE 2154 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by PassiveHeadspace Concentration with Solid Phase Microextrac-tio
9、n (SPME)3. Summary of Practice3.1 Extracts obtained from fire debris samples and ques-tioned liquids analyzed for the presence of ignitable liquidresidues are retained and preserved for potential reanalysis byTest Methods E 1387 or E 1618.4. Significance and Use4.1 The archiving of extracts recovere
10、d from fire debris orliquids submitted in a fire investigation provides a mechanismto preserve extracts and liquids for reanalysis in the event thatsample loss, sample degradation, or failure of the fire debriscontainer occurs during post-analysis storage of fire debrisevidence.4.2 The nature of som
11、e extraction procedures, which maypreclude reanalysis, is considered.4.3 Changes to a preserved sample extract and the length oftime it remains viable under storage conditions are unknown.4.4 The concentration and composition of the ignitableliquid residue or the use of an alternate extraction/conce
12、ntration technique used to preserve a sample extract ofthe fire debris sample may result in different findings betweenthe analysis of the preserved sample and the original analysis.5. Materials5.1 Airtight and Vapor-Tight, Volatile-Free StorageContainersThe following are suggested container types:5.
13、1.1 Septum crimp vials with PTFE-lined seals.5.1.2 Screw cap glass vials with PTFE-lined seals.5.1.3 Polymer evidence bags (this does not include polyeth-ylene or polypropylene-type containers).5.2 Adsorption Media:1This practice is under the jurisdiction of ASTM Committee E30 on ForensicSciences an
14、d is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved March 1, 2008. Published April 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
15、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.5.2.1 Activated charcoal (coconut).5.2.2 Activated charcoal strips.6. Procedure6.1 Passive Headspace Concentratio
16、n with Activated Char-coal (Practice E 1412).6.1.1 Single-Strip Adsorption:6.1.1.1 After analysis, the eluted and analyzed extract maybe retained for preservation. Readsorb the extract onto thecharcoal strip by allowing the eluent to evaporate. Store thecharcoal strip in an appropriate container for
17、 preservation.6.1.1.2 Alternatively, after adsorption and before elution,divide the strip. Use one portion of the strip for analysis. Placethe remaining portion in an appropriate container for preser-vation.6.1.2 Two-Strip Adsorption:6.1.2.1 After adsorption, use one strip for analysis. Place thesec
18、ond strip in an appropriate container for preservation.NOTE 1This procedure requires that the two strips be adsorbedsimultaneously.6.1.3 Adsorbent Package Adsorption:6.1.3.1 After analysis, the eluted and analyzed extract maybe retained for preservation. Readsorb the extract onto theadsorbent packag
19、e by allowing the eluent to evaporate. Storethe adsorbent in an appropriate container for preservation.6.2 Dynamic Headspace (Practice E 1413).6.2.1 After analysis, the eluted and analyzed extract may beretained for preservation. Readsorb the extract onto the adsor-bent by allowing the eluent to eva
20、porate. Store the adsorbent inan appropriate container for preservation.6.3 Solvent Extraction (Practice E 1386).6.3.1 After analysis, the analyzed extract may be retainedfor preservation. Adsorb the extract or a portion of the extracton an adsorption medium and store in an appropriate containerfor
21、preservation.6.3.2 Place any remaining extract in an appropriate con-tainer for preservation.6.4 Liquid Samples.6.4.1 Place the liquid, a portion of the liquid, extract, orrecovered distillate in an appropriate container for preserva-tion.6.4.2 Alternatively, adsorb a portion of the liquid, extract,
22、 orrecovered distillate on an adsorption medium and store in anappropriate container for preservation.6.5 SPME and Headspace Sampling (Practices E 2154 andE 1388).6.5.1 Extracts using these sampling techniques are con-sumed by the analysis and are not amenable to preservation.6.5.2 Alternative separ
23、ation and concentration practicesmay be used when the preservation of extracts is desired.7. Storage of Liquid Samples and Extracts7.1 Label all vials containing samples or extracts accordingto Guide E 1459. Notations regarding any sample or extractpreservation should be maintained in the case notes
24、 and inaccordance with laboratory procedures.7.1.1 Preserved samples and extracts may be released/returned with the evidence as an attachment or enclosure.7.1.2 Alternatively, preserved samples and extracts may becataloged and stored.7.2 Preserved samples and extracts may be stored in con-tainers as
25、 noted in 5.1. Chemical compatibility, vapor pressure,contamination, mechanical strength, and storage conditions areamong the considerations in selection of storage containers.7.3 Preserved samples and extracts may be stored at roomtemperature, under refrigeration, or frozen. Effects of tempera-ture
26、 and freeze-thaw conditions on the stability and viability ofsamples, effectiveness of container sealing, and containerintegrity are factors to consider in selection of thermal storageconditions.7.4 If not returned with the evidence, store preservedsamples and extracts at the laboratory for a period
27、 of time asdirected by laboratory policy and federal, state, or local laws.Follow the procedures set forth in Practice E 1492 to ensurethat the chain of custody is protected.8. Keywords8.1 analysis; archiving; extract preservation; fire debris;forensic science; ignitable liquid residue; sample extra
28、ct;sample preservation; storageASTM 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 determination of the validity of any such patent rights, and the riskof i
29、nfringement 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 revised, either reapproved or withdrawn. Your comments are invited either for revision of this sta
30、ndard 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 may attend. If you feel that your comments have not received a fair hearing you shouldmake your
31、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).E2451082
