title: Rapid simultaneous determination for organophosphorus pesticides in human serum by LC-MS.
abstract: A simple and rapid method was developed for measuring 10 organophosphorus pesticides (acephate, methidathion, dichlorvos, fenthion, EPN, diazinon, phenthoate, malathion, fenitrothion, and cyanophos) in the serum of acute poisoning patients by LC/MS. Following deproteinization by acetonitrile, an aliquot of the biological sample was injected into a C(18) column using 10mM ammonium formate-methanol as the mobile phase. Extraction recoveries were satisfactory and ranged between 60.0 and 108.1% in serum. The limits of detection (LODs) in serum ranged from 0.125 to 1 microg/ml, and the limits of quantitation (LOQs) ranged from 0.25 to 1.25 microg/ml. An excellent linearity was observed for these LOQs up to 8 microg/ml. Intra- and interassay precision and accuracy were satisfactory for most of the pesticides analyzed. In terms of temperature stability, of all the organophosphorus compounds analyzed, dichlorvos and malathion exhibited the most rapid degradations over 24h at room temperature. Methidathion and diazinon remained relatively stable at all temperatures during the entire 4-week testing period. The present method was successfully applied to one actual case of acute poisoning. In conclusion, this method is simple, accurate, and useful for the determination of organophosphorus pesticides and should benefit both clinical and forensic toxicology.
authors.affiliation: Department of Emergency and Critical Care Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan. caf55000@pop12.odn.ne.jp
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Inoue
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saito
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Mase
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Kensuke
authors.initials: K
authors.lastname: Takazawa
authors.forename: Isotoshi
authors.initials: I
authors.lastname: Yamamoto
authors.forename: Sadaki
authors.initials: S
authors.lastname: Inokuchi
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D053593:Forensic Toxicology; D005615:Freezing; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008875:Middle Aged; D015394:Molecular Structure; D062025:Organophosphate Poisoning; D009943:Organophosphorus Compounds / Q000097:blood* / Q000737:chemistry; D010575:Pesticides / Q000097:blood* / Q000737:chemistry / Q000506:poisoning; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013406:Suicide, Attempted; D013997:Time Factors
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides