Multiresidue determination method for organophosphorus, pesticides in serum and whole blood by gas chromatography-mass-selective detection

This paper describes a rapid, specific and sensitive method for the determination of 29 organophosphorus pesticides in blood and serum, involving a rapid solid-phase extraction procedure using Oasis HLB cartridges and gas chromatography coupled to mass-selective detection. The ionization was performed by electron Impact and acquisition in the single ion monitoring mode followed three specific ions per analyte. Extraction recoveries were satisfactory and ranged between 40 and 108% in blood and serum. Limits of detection ranged from 5 to 25 ng/ml and limits of quantitation (LOQs) ranged from 10 to 50 ng/ml, in blood and serum. An excellent linearity was observed from these LOQs up to 1000 ng/ml. Intra- and inter-assay precision and accuracy were satisfactory for most of the pesticides analyzed.