Rapid method for the determination of some organophosphorus insecticides in a small amount of serum in emergency and occupational toxicology cases

A simple and rapid method is described for the estimation of some organophosphorus insecticides in the serum of occupationally exposed persons. The compounds are extracted with a mixture of acetone and diethyl ether (1:1 v/v) in acidic medium and the extraction residue is analyzed by gas chromatography with nitrogen phosphorus detection method. Linearity was acceptable over concentrations from 0.25 to 4.0 μg/mL. The method percentile recovery for the six different organophosphorus insecticides was 86.3% for phorate, 78.3% for dimethoate, 82.3% for malathion, 79.4% for chlorpyrifos, 80.2% for diazinon, and 68.5% for ethion at the μg/mL level. Serum samples of nine workers who had been occupationally exposed to malathion in an insecticide manufacturing factory, were analyzed and malathion was found at low levels in all the samples.