Enzymatic oxidation of diethyldithiocarbamate by xanthine oxidase and its colorimetric assay.

Diethyldithiocarbamate is oxidized in vitro by purified cream xanthine oxidase in the presence of nitro blue tetrazolium and phenazine methosulfate. Disulfiram is formed during the enzymatic or nonenzymatic oxidation. When diethyldithiocarbamate is mixed nonenzymatically with nitro blue tetrazolium, the dye is rapidly reduced, but only in the presence of certain organic solvents. This reaction can be used as a convenient colorimetric assay for diethyldithiocarbamate, which gives a stable color over a wide concentration range.