4.1 This practice is useful for preparing extracts from fire debris for later analysis by gas chromatography-mass spectrometry (GC-MS), see Test Method E1618.
4.2 This is a very sensitive separation procedure, capable of isolating quantities smaller than 0.1 μL of ignitable liquid residue from a sample
4.2.1 Actual recovery will vary, depending on several factors, including adsorption temperature, container size, and competition from the sample matrix.
4.3 This is a potentially destructive technique. Portions of the sample subjected to this procedure may not be suitable for re-sampling. Therefore, a portion of the sample extract should be saved for potential future analysis. Consider using passive headspace concentration as described in Practice E1412.
Область применения1.1 This practice describes the procedure for separation of small quantities of ignitable liquid residues from fire debris samples using the method of dynamic headspace concentration.
1.2 Dynamic headspace concentration uses adsorption and subsequent solvent elution or thermal desorption.
1.3 Both positive and negative pressure systems for adsorption are described, as well as a thermal desorption system.
1.4 While this practice is suitable for successfully extracting ignitable liquid residues over the entire range of concentration, the headspace concentration methods are best used when a high level of sensitivity is required due to a very low concentration of ignitable liquid residues in the sample.
1.5 Alternate separation and concentration procedures are listed in Section 2. If archival of the extract is of importance, then this practice’s thermal desorption procedure, SPME (Practice E2154), and headspace (Practice E1388) sample separation techniques are not recommended unless a portion of the extract can be split and retained. In order to have an archivable extract, then this practice’s sample collection on charcoal, solvent extraction (Practice E1386), or passive headspace concentration (Practice E1412) is recommended.
1.6 This practice offers a set of instructions for performing one or more specific operations. This standard cannot replace knowledge, skill, or ability acquired through appropriate education, training, and experience and should be used in conjunction with sound professional judgment.
1.7 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.