title: Headspace solid phase microextraction for the gas chromatographic analysis of methyl-parathion in post-mortem human samples. Application in a suicide case by intravenous injection.
abstract: A simple and rapid procedure for the determination of methyl-parathion (m-p) in post-mortem biological samples was developed using headspace solid phase microextraction (SPME) and gas chromatography (GC) with nitrogen-phosphorous detection (NPD). Methyl-parathion was extracted on 85 microm polyacrylate SPME fiber. Salt addition, extraction temperature, and extraction time were optimized to enhance the sensitivity of the method. The linearity (y = 0.0473x - 0.0113, R2 = 0.9992) and the dynamic range (0.1-40 microg/ml) were found very satisfactory. The recoveries of methyl-parathion were found to be 46% in spiked human whole blood, 53% in spiked homogenized liver tissue, and 54% in spiked homogenized kidney tissue compared with samples prepared in water. The coefficients of variations for 2, 4, and 20 microg/ml of methyl-parathion in blood ranged from 0.9 to 5.1%, whereas the detection limit of the method was satisfactory (1 ng/ml in aqueous samples, 50 ng/ml in whole blood). The developed procedure was applied to post-mortem biological samples from a 21-year-old woman fatally poisoned (suicide) by intravenous injection of methyl-parathion. The intact insecticide was found in the post-mortem blood at a concentration of 24 microg/ml. No methyl-parathion was detected in the liver, kidneys, and gastric contents.
authors.affiliation: Laboratory of Forensic Medicine and Toxicology, Faculty of Medicine, Aristotle University, 541 24 Thessaloniki, Greece. elpa@med.auth.gr
authors.forename: H
authors.initials: H
authors.lastname: Tsoukali
authors.forename: N
authors.initials: N
authors.lastname: Raikos
authors.forename: G
authors.initials: G
authors.lastname: Theodoridis
authors.forename: D
authors.initials: D
authors.lastname: Psaroulis
mesh_terms: D000328:Adult; D002849:Chromatography, Gas / Q000379:methods*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007306:Insecticides / Q000032:analysis* / Q000506:poisoning; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008743:Methyl Parathion / Q000032:analysis* / Q000506:poisoning; D009584:Nitrogen; D010758:Phosphorus; D015203:Reproducibility of Results; D013405:Suicide; D014867:Water / Q000737:chemistry
chemical_list: D007306:Insecticides; D014867:Water; D010758:Phosphorus; D008743:Methyl Parathion; D009584:Nitrogen