ISSN: 0022-1198
CODEN: JFSCA
Page Count: 7

A Method for Forensic Identification of Vegetable Oil Stains—Rapid Analysis of Carboxylic Acids with Methyl Esterification Using Purge-and-Trap Gas Chromatography/Mass Spectrometry
Sakamoto, K
Graduate School of Science and Engineering, Saitama University,

Ehara, Y

Marumo, Y
National Research Institute of Police Science,

(Received 2 December 2000; accepted 13 March 2001)

Abstract

A simple method using purge-and-trap gas chromatography/mass spectrometry (P&T-GC/MS) for forensic examination of oil stains was studied. Carboxylic acids, chosen as target components for discrimination of oil samples, were extracted from stains with ether, methyl esterified by tetramethylammonium hydroxide, and analyzed by P&T-GC/MS. Vegetable oils were discriminated according to their carboxylic acid compositions. Carboxylic acid composition was independent of the substrate material of the stain. Although the carboxylic acid composition of the oil changed on exposure to sunlight, identification of oil was possible for oil stains that had been in the shade, if analysis was made within 20 days.

Keywords:
forensic science, vegetable oil, purge-and-trap gas chromatography, oil stain, methyl esterification, carboxylic acid, substrate material, exposure, steroid analysis

Paper ID: JFS15172J
DOI: 10.1520/JFS15172J
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