Oxidation of Diazinon for the Sensitive Detection By Cholinesterase-Based Bioanalytical Method

The conversion of diazinon, the model compound for OPs, to more potent AChE inhibitor diazoxon was investigated, using enzyme myeloperoxidase (MPO) as an oxidant. The aim was to enhance its inhibitory power in order to develop rapid, effective and specific acethylcholinesterase (AChE)-based bioanalytical method for its detection in environment. 5-min incubation of 1 x 10(-5) M - 1 x 10(-7) M diazinon with 100 nM MPO increased the degree of AChE inhibition from 80 to 10% due to the formation of diazoxon, compared to the control values for samples containing the same diazinon concentrations in untreated samples. The calibration graph for diazinon detection with AChE assay after incubation with MPO was constructed. While the lower detection limit of diazinon (10% AChE inhibition) before oxidation was ca. 1 x 10(-5) M, the detection limit after oxidation was below 1 x 10(-8) M