Standard Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Dynamic Headspace Concentration onto an Adsorbent Tube

Importancia y uso:

5.1 This practice is useful for preparing extracts from fire debris for subsequent qualitative analysis by gas chromatography mass spectrometry, see Test Method E1618.

5.2 The sensitivity of this practice is such that a sample consisting of a laboratory tissue onto which as little as 0.1 µL of ignitable liquid has been deposited, in an otherwise empty sample container, will result in an extract that is sufficient for identification and classification using Test Method E1618 (1).

5.2.1 Recovery from fire debris samples will vary, depending on factors including debris temperature, adsorbent temperature, container size, adsorptive material, headspace volume, sampling time and flow rate, and adsorptive competition from the sample matrix (2).

5.3 The principal concepts of dynamic headspace concentration are similar to those of static headspace concentration (Practice E3189). The dynamic headspace concentration technique can be more sensitive than the static headspace concentration technique. However, sample containers subjected to dynamic headspace concentration could be unsuitable for re-sampling.

5.3.1 Dynamic headspace concentration alters the original composition of the test sample because a portion of the original headspace from the sample container is removed and exchanged with dry inert gas or air. A portion of the concentrated headspace sample should be preserved for potential future analysis, if possible and if required, in accordance with Practice E2451.

5.4 Common solid adsorbent/desorption procedure combinations in use are activated carbon/solvent elution, and Tenax4 TA/thermal desorption.

5.5 Solid adsorbent/desorption procedure combinations not specifically described in this standard can be used as long as the practice has been validated as outlined in Section 11.

Subcomité:

E30.13

Referida por:

E3197-23, E1732-24E01, E1618-19, E1386-23, E1388-24, E0860-22, E1412-19, E3189-19, E2451-21, E2997-16, E3245-20E01, E2881-18

Volúmen:

14.02

Número ICS:

13.220.99 (Other standards related to fire protection)

Palabras clave:

activated carbon; adsorbent tube; dynamic headspace concentration; elution; fire debris samples; forensic science; gas chromatography-mass spectrometry; ignitable liquid residues; Tenax TA; thermal desorption;