1、Designation: E2997 16Standard Test Method forAnalysis of Biodiesel Products by Gas Chromatography-Mass Spectrometry1This standard is issued under the fixed designation E2997; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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 test method covers the analysis and identificationof the fatty acid methyl esters (FAMEs) and petroleum disti
3、l-late components of biodiesel products.1.2 This test method is suitable for identifying the compo-nents of biodiesel products in extracts of debris samples or inliquid samples.1.3 The identification of a specific source of the FAMEs orthe proportion of the blend of biodiesel requires additionalanal
4、ysis and is beyond the scope of this test method.1.4 This test method cannot replace the requisiteknowledge, skills, or abilities acquired through appropriateeducation, training, and experience and should be used inconjunction with sound professional judgment.1.5 The values stated in SI units are to
5、 be regarded asstandard. No other units of measurement are included in thisstandard.1.6 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
6、 determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E620 Practice for Reporting Opinions of Scientific or Tech-nical ExpertsE1386 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Solvent ExtractionE1412 Practi
7、ce for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Passive Headspace Concen-tration With Activated CharcoalE1413 Practice for Separation of Ignitable Liquid Residuesfrom Fire Debris Samples by Dynamic Headspace Con-centrationE1492 Practice for Receiving, Documenting, Storing,
8、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 Headspac
9、e Concentration with Solid Phase Microex-traction (SPME)E2451 Practice for Preserving Ignitable Liquids and Ignit-able Liquid Residue Extracts from Fire Debris SamplesE2881 Test Method for Extraction and Derivatization ofVegetable Oils and Fats from Fire Debris and LiquidSamples with Analysis by Gas
10、 Chromatography-MassSpectrometry3. Summary of Test Method3.1 Traditional ignitable liquid analysis will be used toidentify biodiesel products.3.2 The debris sample is extracted or an aliquot of a liquidis extracted or diluted and analyzed by gas chromatography-mass spectrometry (GC-MS).3.3 If fatty
11、acid methyl esters (FAMEs) are suspected,further solvent extraction and analysis on a FAME-specificcolumn may be required.3.4 Specific chemical components (fatty acid methyl esters)are identified by their retention times and mass spectra.4. Significance and Use4.1 This test method specifically ident
12、ifies fatty acid methylesters and petroleum distillates found in biodiesel products.Derivatization is not necessary to identify FAMEs.4.1.1 This test method is useful when biodiesel products aresuspected as a fuel source in a fire or a fuel product case andthe identification of the “bio” portion of
13、the fuel is of interest.4.1.2 The identification of biodiesel in samples from a firescene can support the field investigators opinion regarding theorigin and cause of the fire or provide investigative leads.1This test method is under the jurisdiction ofASTM Committee E30 on ForensicSciences and is t
14、he direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved March 1, 2016. Published April 2016. DOI: 10.1520/E2997-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
15、ards 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. United States14.1.3 The identification of biodiesel in a sample of fuel froma dispensing container or fuel tank
16、 can support the fieldinvestigators findings in a fuel product tampering investiga-tion.4.2 FAMEs can be identified in debris samples using head-space extraction techniques and GC-MS.4.2.1 Solvent extraction may be required to further identifyand characterize the FAME content in biodiesel.4.2.2 The
17、presence of FAMEs and petroleum diesel is astrong indication of a biodiesel product, as FAMEs are notnaturally occurring.4.3 Biodiesel products can be identified in liquid samples byGC-MS after appropriate solvent dilution or extraction.4.4 Biodiesel is available in different blends, where B100 is10
18、0 % biodiesel (typically 100 % transesterified vegetable oilsor recycled restaurant greases) and B2 is 2 % biodiesel and 98% petroleum diesel, with variations in between.4.5 This test method is a sensitive technique and can detectquantities as small as 7 L of biodiesel residue in an extractfrom a de
19、bris sample.4.6 This test method can be hampered by coincident extrac-tion of interfering compounds present in the debris samples.4.7 Depending on the extraction method used, this could bea destructive technique and whenever possible the entiresample should not be used for the procedure. Solvent ext
20、ractedportions of the sample are not suitable for resampling.4.8 Alternate methods of extraction or analysis exist andmay be suitable for use in obtaining similar results andconclusions.5. Apparatus5.1 Gas ChromatographA chromatograph capable of us-ing capillary columns and being interfaced to a mas
21、s spectrom-eter.5.1.1 Sample Inlet SystemA sample inlet system that canbe operated in either split or splitless mode with capillarycolumns; the inlet system may use on-column technology.5.1.2 ColumnA non-polar capillary, bonded phase, meth-ylsilicone or phenylmethylsilicone column or equivalent, or
22、apolar capillary, bonded phase column, such as a cyanopropyl-based fatty acid specific column or equivalent, may be used todetermine the presence of fatty acids.5.1.2.1 A polar capillary, bonded phase column, such as acyanopropyl-based fatty acid specific column or equivalentshall be used to perform
23、 comparative analysis between speci-mens of questioned neat liquid samples, debris extracts, orboth.5.1.2.2 Any column length or temperature program condi-tions may be used for the polar column provided that eachcomponent of the reference mixture (see 6.6.2) is adequatelyseparated.5.1.3 GC OvenA col
24、umn oven capable of reproducibletemperature program operation in the range from 50 to 300C.5.2 Mass SpectrometerCapable of acquiring mass spectrafrom m/z 40 to m/z 400 with unit resolution or better, withcontinuous data output.5.2.1 Sensitivity and ResolutionThe system shall be ca-pable of detecting
25、 each component of the reference or testmixture (see 6.6) and providing sufficient ion intensity data toidentify each component, either by computer search of a massspectral library or by comparison with reference spectra.5.3 Data StationA computerized data station capable ofstoring time sequenced ma
26、ss spectral data from sample runs.5.3.1 Data HandlingThe data system shall be capable ofperforming, either through its operating system or by userprogramming, various data handling functions, including inputand storage of sample data files, generation of extracted ionprofiles, searching data files f
27、or selected compounds, andqualitative and semi-quantitative compound analysis.5.3.2 Mass Spectral LibrariesThe system shall be capableof retrieving a specified mass spectrum from a data file andcomparing it against a library of mass spectra available to thedata system. This capability is considered
28、an aid to the analyst,who will use it in conjunction with chromatographic data andknown reference materials to identify unknown components.5.4 SyringesA syringe capable of introducing a samplesize in the range from 0.1 to 10.0 L.5.5 Steam bath or heating device, for use in warmingsample extracts in
29、containers used during evaporation steps.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals should beused in all tests. It is intended that all reagents conform to thespecifications of the Committee on Analytical Reagents of theAmerican Chemical Society.3Other grades may be used,
30、provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 SolventA suitable solvent, such as n-pentane, carbondisulfide, or other solvent that will not interfere with theanalysis.6.2.1 Solvent purity can b
31、e verified by evaporating to atleast twice the extent used in the analysis and analyzing theevaporated solvent in accordance with Test Method E1618.6.3 Filter apparatus, free of extractable hydrocarbons, oils,and fats.6.4 Evaporation accelerants, compressed dry nitrogen, fil-tered air, or inert gas
32、used in the concentration of solventextracts.6.5 Carrier gas, helium or hydrogen of purity 99.995 % orhigher.6.6 Reference and Test Mixtures:6.6.1 Refer to Test Method E1618, Section 6, for theappropriate test mixture for the hydrocarbon portion of theanalysis.6.6.2 Refer to Test Method E2881, Secti
33、on 6, for theappropriate reference mixture for the “bio” portion of theanalysis.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC.E2997 1626.6.3 Reference biodiesel products should be obtained forcomparison and identification purposes. Typical chr
34、omato-grams of B100 and B20 on a non-polar fire debris column areshown in Fig. 1. Typical chromatograms of B100 and B20 ona fatty acid specific polar column are shown in Fig. 2.6.7 Glassware or labware, clean glassware (beakers, testtubes, and vials) or disposable labware free of extractablehydrocar
35、bons, oils, and waxes.7. Equipment Calibration and Maintenance7.1 Verify the consistent performance of the chromato-graphic instrument by using blanks and a known concentrationof the appropriate reference or test mixture (see 6.6). Optimizegas flow periodically.7.2 Tune and check calibration of mass
36、 spectrometer.7.2.1 Ensure proper operation of the mass spectrometerusing perfluorotributylamine (PFTBA), or another appropriatecalibration standard, according to the instrument manufactur-ers specifications, prior to use. This should be done at leastevery day that the instrument is used or in accor
37、dance withmanufacturers recommendations.7.2.2 Maintain tuning documentation as a portion of thequality control documentation.7.3 Equipment Maintenance:7.3.1 Change septa, replace gold seals, trim front end ofcolumn, and clean or replace injector liners on a periodic basisto avoid sample contaminatio
38、n by carryover of residual mate-rial from previous sample injections.8. Sample Handling/Analysis Procedure8.1 Observe the appropriate procedures for handling anddocumentation of all submitted samples as described in Prac-tice E1492.8.1.1 Open and examine the fire debris or liquid sample inorder to d
39、etermine that it is consistent with its description.Resolve any discrepancies between the submitters descriptionof the sample and the analysts observations prior to thecompletion of the report.8.2 Only specimens of appropriate dilution should be ana-lyzed on a GC-MS system.8.3 Analyze solvent blanks
40、 at least once each day that theinstrument is used; maintain these analysis records as a portionof the quality control documentation. This will verify the purityof the solvent and potentially detect carryover or contamina-tion.8.4 Clean syringes thoroughly between injections to ensureno carryover.8.
41、4.1 Conduct carryover studies, and maintain records thatdemonstrate the adequacy of laboratory procedures to preventcarryover.8.4.2 Running solvent blanks between each specimen isrecommended but not required if studies demonstrate that thecleaning procedure is adequate to prevent carryover.8.5 Maint
42、ain reference files of known biodiesel productsthat have been prepared and analyzed in the same manner asthe questioned samples.8.6 Extract a fire debris sample using one or more tech-niques as described in Practices E1386, E1412, E1413,orE2154 to isolate ignitable liquid residues and FAME compo-nen
43、ts for analysis.8.7 WarningExtract a fire debris sample using headspacetechniques prior to performing any solvent extraction if theidentification of all classes of ignitable liquids is of interest.8.8 An aliquot of a liquid sample is extracted or diluted asappropriate.8.9 Analyze the sample specimen
44、(s) along with referencematerials or standards, as necessary, to identify the componentsof biodiesel products and other ignitable liquid residues inaccordance with Test Method E1618 (also see Fig. 1).8.9.1 If any FAMEs are detected, additional analysis may berequired to further identify the FAME com
45、ponents. PracticeE1386 may be followed to extract a portion of the originalsample, or the original extract can be concentrated, followed byanalysis on a FAME-specific column using conditions assuggested in Fig. 2 and 5.1.2.2.8.9.2 Extracts may be further concentrated for re-analysis.Place the extrac
46、t in a chemical fume hood and evaporate atroom temperature to a suitable final volume. Compressed drynitrogen, filtered air, or an inert gas can be used to accelerateevaporation. Using heat to facilitate concentration is acceptablefor suspected biodiesel samples as polymerization does notoccur with
47、FAMEs.8.9.2.1 WarningDo not evaporate an extract to dryness iflighter ignitable liquid residues were identified and no othersample extract is available for archiving and long-term storage.8.10 See AnnexA1 for sample and extract storage guidance.9. Data Analysis and Interpretation9.1 The identificati
48、on of FAMEs in liquids and fire debrisextracts is performed using retention time and mass spectraldata compared with certified standards or reference materials(see 6.6). The presence of FAMEs, with or without petroleumdiesel, is an indication of biodiesel, as FAMEs are not naturallyoccurring. Refer
49、to Test Method E1618 for identification ofpetroleum distillates. Typical chromatograms of B100 and B20on a traditional non-polar fire debris column collected follow-ing Practice E1412 are shown in Fig. 3.9.1.1 WarningSome household and commercialproducts, such as some laundry detergents and fabric softeners,may contain FAMEs. Debris samples should be thoroughlyinspected after analysis for items or materials that could be asource of FAMEs in an extract other than a biodiesel fuel.9.2 Extracted ion Profiling (EIP):9.2.1 Extracted ion profiles may be used to eluci
