comparison of gas chromatographic and anti-cholinesterase methods for measuring parathion metabolism in vitro

The interchangeability of the gas chromatographic and anti-cholinesterase assays for determining paraoxon is tested by performing analyses by both methods on the same samples. The samples are incubation mixtures of parathion with liver homogenates prepared from mice subjected to different treatments. The limit of paraoxon detection by the anti-cholinesterase method is 0.5 nmoles in the total incubate, while the gas chromatography is reliable only to about 1 nmole. The anti-cholinesterase method is more rapid and convenient.