DETERMINATION OF SODIUM DIETHYLDITHIOCARBAMATE (IMUTHIOL) AND ITS S-METHYL METABOLITE BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY - USE OF DEUTEROMETHYL IODIDE DERIVATIZATION

A gas-chromatographic-mass spectrometric method is described to measure the plasma concentration of sodium diethyldithiocarbamate (ditiocarb sodium, DEDTC-Na), the active ingredient of Imuthiol(R), a drug found to be active in the opportunistic infections occurring in AIDS, and its S-methyl metabolite. Plasma samples are treated with deuteromethyl iodide and DEDTC-Na is transformed into its deuteromethyl ester, which is then co-extracted with the S-methyl metabolite. Gas chromatography-mass spectrometry and selected-ion monitoring allow the specific determination of both compounds. Linear calibration curves were obtained up to 4000 ng/ml. This method has been successfully applied for pharmacokinetic studies after Imuthiol and disulfiram, the dimer of DEDTC, were administered to humans.