Simple determination of dichlorvos in cases of fatal intoxication by gas Chromatography-Mass spectrometry

Abstract

Dichlorvos (DDVP) is an organophosphorous insecticide which is classified as “highly hazardous” Class 1B chemical by World Health Organization (WHO) and largely misused for the purpose of self-poisoning in developing countries. Forensic toxicology laboratories are routinely encountering cases of pesticide poisoning due to their fatal intoxication. Herein; a method is described based on vortex-assisted dispersive liquid–liquid microextraction (VA-DLLME) coupled with Gas Chromatography-Mass Spectrometry (GC–MS) for the determination of an organophosphorous insecticide; dichlorvos (DDVP) in human autopsy samples (blood, stomach content and liver). Under the optimum conditions, the method was found to be linear in the range of 0.5–10 µg mL−1 and 1.5–10 µg g−1 for blood and tissue samples, respectively. Limit of quantification was set at 0.55 µg mL−1 and 1.1 µg g−1 for blood and tissue samples, respectively. Intraday and inter-day precisions were less than 8 and 12 %, respectively. Good recoveries in the range of 86–95 % were obtained for the proposed procedure. The method has been satisfactorily applied for the determination of DDVP in autopsy samples from two different cases received in our laboratory. In comparison to previous methods; the proposed method is relatively short, high sample throughput, inexpensive and adheres to the principles of green analytical chemistry (GAC) for determination of DDVP in human autopsy samples. The method can be adopted in forensic toxicological laboratories for analysis of DDVP in autopsy samples. In addition, the green character of the proposed method was evaluated using ComplexGAPI procedure.