Citation

Contreras PA, Houck SS, Davis WM, Yu JC. J. Forensic Sci. 2013; 58(1): 210-216.

Affiliation

Master of Science in Forensic Science Program, College of Criminal Justice, Sam Houston State University, 1003 Bowers Blvd., Huntsville, TX 77341. Harris County Institute of Forensic Sciences, 1885 Old Spanish Trail, Houston, TX 77054.

Copyright

(Copyright © 2013, American Society for Testing and Materials, Publisher John Wiley and Sons)

DOI

10.1111/j.1556-4029.2012.02194.x

PMID

22607121

Abstract

  In this case report, potential interferences from an improvised fire-extinguishing agent, a dishwashing liquid, containing linear alkylbenzene sulfonates (LAS), was studied. The presence of linear alkylbenzenes (LABs) in the fire debris sample was identified from the summed ion profile (SIP) analysis. It was found that the LAS from dishwashing liquids produce LABs by thermal degradation. Direct pyrolysis of a LAS-containing dishwashing liquid at 300°C yielded a distribution of LABs in the SIP. LABs began to break down at pyrolysis temperatures between 450 and 500°C and completely break down by 800°C. Observed pyrolysis breakdown products of LABs included toluene, ethylbenzene, meta-, para-, and ortho-xylenes, propylbenzene, indane, naphthalene, and 1- and 2-methylnaphthalenes. These data suggested the presence of LABs in fire debris evidence might complicate subsequent analysis because their breakdown products contained some of the target compounds common to ignitable liquid identification. Therefore, a positive determination of the presence of foreign ignitable liquids should be carefully evaluated when there is a presence of LABs in the SIP.

Language: en