Significance and Use 4.1 This test method specifically identifies fatty acid methyl esters 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 are suspected as a fuel source in a fire or a fuel product case and the identification of the “bio” portion of the fuel is of interest. 4.1.2 The identification of biodiesel in samples from a fire scene can support the field investigator’s opinion regarding the origin and cause of the fire or provide investigative leads. 4.1.3 The identification of biodiesel in a sample of fuel from a dispensing container or fuel tank can support the field investigator’s findings in a fuel product tampering investigation. 4.2 FAMEs can be identified in debris samples using headspace extraction techniques and GC-MS. 4.2.1 Solvent extraction may be required to further identify and characterize the FAME content in biodiesel. 4.2.2 The presence of FAMEs and petroleum diesel is a strong indication of a biodiesel product, as FAMEs are not naturally occurring. 4.3 Biodiesel products can be identified in liquid samples by GC-MS after appropriate solvent dilution or extraction. 4.4 Biodiesel is available in different blends, where B100 is 100 % biodiesel (typically 100 % transesterified vegetable oils or 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 detect quantities as small as 7 μL of biodiesel residue in an extract from a debris sample. 4.6 This test method can be hampered by coincident extraction of interfering compounds present in the debris samples. 4.7 Depending on the extraction method used, this could be a destructive technique and whenever possible the entire sample should not be used for the procedure. Solvent extracted portions of the sample are not suitable for resampling. 4.8 Alternate methods of extraction or analysis exist and may be suitable for use in obtaining similar results and conclusions.Scope 1.1 This test method covers the analysis and identification of the fatty acid methyl esters (FAMEs) and petroleum distillate components of biodiesel products. 1.2 This test method is suitable for identifying the components of biodiesel products in extracts of debris samples or in liquid samples. 1.3 The identification of a specific source of the FAMEs or the proportion of the blend of biodiesel requires additional analysis and is beyond the scope of this test method. 1.4 This test method cannot replace the requisite knowledge, skills, or abilities acquired through appropriate education, training, and experience and should be used in conjunction with sound 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 responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
