摘要：The analyses of dialkylphosphates, aqueous metabolites or degradation products of organophosphorus pesticides, with extractive pentafluorobenzylation in the presence of polymeric phase-transfer catalysts (tri-phase catalysts) were investigated. Dialkylthiophosphates and dialkyldithiophosphates (alkyl=methyl, ethyl) in aqueous samples were extracted and derivatized in more than 98% yield by pentafluorobenzyl bromide in 15 min at 40°C using tri-n-butyl methyl phosphonium bromide polymer bound as a tri-phase catalyst and MIBK as an organic solvent. Dimethylphosphate and diethylphosphate were also derivatized in 43% and 100% yields, respectively, in the presence of this tri-phase catalyst in 90 min at 90°C. The simultaneous analyses of these 6 phosphates in the spiked urine sample were carried out with excellent detection limits, 0.44-0.79 ppm by scan-mode GC-MS and 0.027-0.081 ppm by ECD-GC) using this tri-phase procedure.
关键词：dialkyl phosphate;extractive derivatization;pentafluorobenzylation;polymeric phase transfer catalyst;tri-phase catalyst;phase-transfer reaction;metabolite;GC;electron capture detector;GC-MS
