Rapid and sensitive on-line precolumn purification and high-performance liquid chromatographic assay for disulfiram and its metabolites.

The disulfiram (Antabus) metabolites diethyldithiocarbamate, diethyldithiocarbamate methyl ester, carbon disulphide and bis(diethyldithiocarbamato) copper complex were quantitatively analysed from directly injected heparin plasma by reversed-phase high-performance liquid chromatography. The highly volatile metabolite, carbon disulphide, was converted to the methyl ester of dimethyldithiocarbamate before chromatography. The analytical procedure is simple and does not require sample preparation or addition of an internal standard, and the compounds are eluted from the columns in 15 min. After automated on-line precolumn enrichment, the parent compound and biotransformation products could be back-flushed and chromatographed on an ordinary reversed-phase column. The influence of plasma protein binding on the constituents in the precolumn enrichment step was also investigated. Dissociation and partition of constituents from plasma proteins gave a complete retardation on the precolumn. The time courses of diethyldithiocarbamate and its methyl ester were followed in patients receiving therapeutic doses of disulfiram.