Biological monitoring of pesticide exposure: a review of analytical methods.

The determination of urinary alkylphosphates monitors occupational exposure to organophosphorus pesticides and insecticides. This paper describes a method for the quantitative determination of the following metabolites: O,O-dimethylphosphate (DMP), O,O-diethylphosphate (DEP), O,O-diethylthiophosphate (DETP), O,O-dimethyldithiophosphate (DMDTP), O,O-diethyldithiophosphate (DEDTP), and O,O-dimethylthiophosphate (DMTP). The compounds are derivatized with pentafluorobenzylbromide into pentafluorobenzyl esters which are determined by gas chromatography with a capillary column of intermediate polarity and a flame photometric detector specific for phosphorus. Before the analytical gas chromatographic stage, the urinary extracts are purified on Isolute TM SPE CN columns. The proposed method has a limit of detection of 2-3 pg/L at 62.5 pg/L and a mean recovery of the purification stage of 85.8-101.0% for all six compounds. The coefficient of variation of the analytical procedure was 7.9-11.9% for the six compounds. The low detection limits make this method suitable also for determining the six metabolites in the general population.

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Analytical method for the determination of urinary alkylphosphates in subjects occupationally exposed to organophosphorus pesticides and in the general population.

The rate of urinary excretion of phosalone residues in occupationally exposed persons.

A gas Chromatographic determination of traces of alkali metal O,O-diethyl phosphorodithioates is described. The salts were converted into a volatile derivative by alkylation with diazomethane. The product was identified by gas chromatography-mass spectrometry. With aqueous samples a linear relationship of peak height to amount of salt was obtained in the range 0.04–1 ng and for urine samples a calibration curve was constructed. The detection limit (signal to noise ratio 4/1) was 40 pg of salt. The procedure was successfully used for monitoring phosalone absorption by occupationally exposed persons.

M. Stipcević

Papers

Gas chromatographic determination of alkali metal O,O-diethyl phosphorodithioate present in trace amounts

Determination of dithiophosphoric acid ester residues in urine samples