Simple determination of 22 organophosphorous pesticides in human blood using headspace solid-phase microextraction and gas chromatography with mass spectrometric detection

A simple and rapid procedure for the determination of 22 organophosphorous pesticides (bromophos-ethyl, bromophos-methyl, chlorfenvinphos, chlorpyriphos, demethon-S-methylsulfon, diazinon, dichlorvos, dicrotophos, dimethoate, disulfoton, edifenphos, fenitrothion, fenthion, malathion, methidathion, mevinphos, monocrotophos, omethoate, parathion-ethyl, parathion-methyl, phosphamidon, and quinalphos) in human blood using headspace (HS) solid-phase microextraction (SPME) and gas chromatography (GC)-mass spectrometry (MS) is presented. The effects of various sample additions, incubation temperatures, absorption times, desorption times, and depths of fiber insertion into the injection port of the GC are optimized to enhance the sensitivity of the procedure. The recoveries of spiked blood samples are determined between 70% and 95% compared with samples prepared in water, and absolute recoveries are in the range between 0.1% and 19.6%. For quantitation in the single ion monitoring mode, linearity is established over concentration ranges from 0.025 to 5.0 pg/g with excellent coefficients of correlation (0.991-0.998). The detection limits are in the range between 0.01 and 0.3 pg/g. The time for analysis is 44 min per sample including extraction and GC-MS analysis. HS-SPME in combination with GC-MS is an effective method for the determination of organophosphorous pesticides in human blood and shows a great potential for use in rapid on-site analytical work, which is highly demanded in clinical and forensic toxicology.