1、Designation: E2451 13Standard Practice forPreserving Ignitable Liquids and Ignitable Liquid ResidueExtracts from Fire Debris Samples1This standard is issued under the fixed designation E2451; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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 describes procedures for preserving resi-dues of ignitable liquids in extracts obta
3、ined 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 from
4、 fire debrissamples. The changes that may occur under various storageconditions have not been fully documented.1.3 This practice cannot replace knowledge, skill, or abilityacquired through appropriate education, training, and experi-ence and should be used in conjunction with sound profes-sional jud
5、gment.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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Refere
6、nced Documents2.1 ASTM Standards:2E1386 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Solvent ExtractionE1388 Practice for Sampling of Headspace Vapors from FireDebris SamplesE1412 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Passi
7、ve Headspace Concen-tration With Activated CharcoalE1413 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Dy-namic Headspace ConcentrationE1459 Guide for Physical Evidence Labeling and RelatedDocumentationE1492 Practice for Receiving, Documenting, S
8、toring, andRetrieving Evidence in a Forensic Science LaboratoryE1618 Test Method for Ignitable Liquid Residues in Extractsfrom Fire Debris Samples by Gas Chromatography-MassSpectrometryE2154 Practice for Separation and Concentration of Ignit-able Liquid Residues from Fire Debris Samples by Pas-sive
9、Headspace Concentration with Solid Phase Microex-traction (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 Method E1618.4. Significance a
10、nd Use4.1 The archiving of extracts recovered 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
11、of fire debrisevidence.4.2 The nature of some 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
12、 or the use of an alternate extraction/concentration 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 StorageContainersTh
13、e following are suggested container types:5.1.1 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).1This practice is under the jurisdiction of ASTM Committee E30
14、 on ForensicSciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved June 1, 2013. Published July 2013. Originally approvedin 2008. Last previous edition approved in 2008 as E2451 08. DOI: 10.1520/E2451-13.2For referenced ASTM standards, visit the A
15、STM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Unit
16、ed States15.2 Adsorption Media:5.2.1 Activated charcoal (coconut).5.2.2 Activated charcoal strips.6. Procedure6.1 Passive Headspace Concentration with Activated Char-coal (Practice E1412).6.1.1 Single-Strip Adsorption:6.1.1.1 After analysis, the eluted and analyzed extract maybe retained for preserv
17、ation. Readsorb the extract onto thecharcoal strip by allowing the eluent to evaporate. Store thecharcoal strip in an appropriate container for preservation.6.1.1.2 Alternatively, after adsorption and before elution,divide the strip. Use one portion of the strip for analysis. Placethe remaining port
18、ion 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 thesecond strip in an appropriate container for preservation.NOTE 1This procedure requires that the two strips be adsorbedsimultaneously.6.1.3 Adsorbent Package Ad
19、sorption:6.1.3.1 After analysis, the eluted and analyzed extract maybe retained for preservation. Readsorb the extract onto theadsorbent package by allowing the eluent to evaporate. Storethe adsorbent in an appropriate container for preservation.6.2 Dynamic Headspace (Practice E1413).6.2.1 After ana
20、lysis, the eluted and analyzed extract may beretained for preservation. Readsorb the extract onto the adsor-bent by allowing the eluent to evaporate. Store the adsorbent inan appropriate container for preservation.6.3 Solvent Extraction (Practice E1386).6.3.1 After analysis, the analyzed extract may
21、 be retainedfor preservation. Adsorb the extract or a portion of the extracton an adsorption medium and store in an appropriate containerfor 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
22、, extract, orrecovered distillate in an appropriate container for preserva-tion.6.4.2 Alternatively, adsorb a portion of the liquid, extract, orrecovered distillate on an adsorption medium and store in anappropriate container for preservation.6.5 SPME and Headspace Sampling (Practices E2154 andE1388
23、).6.5.1 Extracts using these sampling techniques are con-sumed by the analysis and are not amenable to preservation.6.5.2 Alternative separation and concentration practicesmay be used when the preservation of extracts is desired.7. Storage of Liquid Samples and Extracts7.1 Label all vials containing
24、 samples or extracts accordingto Guide E1459. Notations regarding any sample or extractpreservation should be maintained in the case notes 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 A
25、lternatively, preserved samples and extracts may becataloged and stored.7.2 Preserved samples and extracts may be stored in con-tainers as noted in 5.1. Chemical compatibility, vapor pressure,contamination, mechanical strength, and storage conditions areamong the considerations in selection of stora
26、ge containers.7.3 Preserved samples and extracts may be stored at roomtemperature, under refrigeration, or frozen. Effects of tempera-ture and freeze-thaw conditions on the stability and viability ofsamples, effectiveness of container sealing, and containerintegrity are factors to consider in select
27、ion of thermal storageconditions.7.4 If not returned with the evidence, store preservedsamples and extracts at the laboratory for a period of time asdirected by laboratory policy and federal, state, or local laws.Follow the procedures set forth in Practice E1492 to ensure thatthe chain of custody is
28、 protected.8. Keywords8.1 analysis; archiving; extract preservation; fire debris;forensic science; ignitable liquid residue; sample extract;sample preservation; storageASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin t
29、his 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 committee and must
30、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 meeting of there
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32、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E2451 132
