Citation

Ohta H, Mori M, Nakajima H, Kanamori T. J. Can. Soc. Forensic Sci. 2006; 39(3): 141-151.

Copyright

(Copyright © 2006, Canadian Society of Forensic Science, Publisher Informa - Taylor and Francis Group)

DOI

10.1080/00085030.2006.10757143

PMID

unavailable

Abstract

Diazinon is an organophosphorus insecticide with a long history, that is widely used throughout the world. It is involved in many cases of suicide or accidental intoxication. Diazinon is considered to be relatively stable under normal conditions, but often undergoes self-decomposition during storage for unknown reasons. We report a case of suicide by ingestion of completely decomposed diazinon. The victim's stomach contents and the liquid that the victim drank underwent forensic examinations. The constituents of the liquid sample were detected from the stomach contents by conventional forensic analytical methods such as thin-layer chromatography and gas chromatography--mass spectrometry. Diazinon itself was not detected in either sample, but several decomposition products of diazinon were detected. In particular, monothiono-TEPP, which is much more toxic than diazinon itself, was detected as a major component. Therefore, in this case, the cause of death was thought to be poisoning by monothiono-TEPP and/or other ingredients such as xylenes. The most abundant components in the samples were 6,6′-thiobis (2-isopropyl-4-methylpyrimidine) and 2-isopropyl-4-ethylthio-6-methylpyrimidine, which are known to be characteristic degradation products of diazinon. These compounds were easily detected, thus providing persuasive evidence that the liquid the victim drank was decomposed diazinon.