Quantitative Determination of Paraquat in a Fatal Intoxication by HPLCÐDAD following Chemical Reduction with Sodium Borohydride

Published: Journal of Analytical Toxicology, Volume 24, Number 2, March, pp.116-121

Quantitative Determination of Paraquat in a Fatal Intoxication by HPLC–DAD following Chemical Reduction with Sodium Borohydride
K. Arys¹, J. Van Bocxlaer1, K. Clauwaert¹, W. Lambert¹, M. Piette², C. Van Peteghem¹, and A. De Leenheer¹
¹Laboratorium voor Toxicologie, Universiteit Gent, Faculteit Farmaceutische Wetenschappen, Harelbekestraat 72, B-9000 Gent, Belgium and ²Laboratorium voor Gerechtelijke Geneeskunde, Faculteit Geneeskunde, Universiteit Gent, J. Kluyskensstraat 29, B-9000 Gent, Belgium

A fatality due to a massive ingestion of paraquat is presented. Screening by enzyme-multiplied immunoassay of postmortem blood and urine disclosed the presence of tricyclic antidepressants (in urine only), benzodiazepines, cotinine, and caffeine. Further analysis of blood, urine, and stomach contents with thin-layer chromatography, high-performance liquid chromatography (HPLC), and gas chromatography confirmed the results found in the preliminary routine screening. It also revealed the presence of paraquat in blood, urine, and stomach contents, of diethyl parathion in urine and stomach contents, and of mevinphos in blood and stomach contents. Quantitation of paraquat was performed using HPLC with diode-array detection. Sample preparation involved a protein-precipitation step using trichloroacetic acid (necessary only for blood and tissue homogenate), followed by a chemical reduction with sodium borohydride of the fully ionized paraquat to a diene, which is amenable to solvent extraction. Quantitative results were obtained for all postmortem matrices available: blood, 5.05 mg/L; urine, 6.00 mg/L; stomach contents, 17.2 g/L; liver, 4.86 mg/kg; and kidney, 80.6 mg/kg. The paraquat distribution in this case is compared with analytical findings reported in the literature. As would be expected, concentrations found in fatal paraquat intoxications display large differences. The data presented illustrate the outspoken lethal nature of the herbicide paraquat and the ongoing appearance of this compound in deadly accidental and suicidal poisonings.

Reproduction of editorial content of this journal is prohibited without publisher’s permission.

This article is available in its entirety by fax for $4.00 per page.
Visa or MasterCard accepted.

To order electronically click here
or call: 847-647-2900 ext. 1323
or fax request to: 847-647-1155.

Please indicate JAT volume and issue along with page numbers.