Liquid chromatographic determination of mitomycin C in human plasma and urine

A method is given for the determination of the antineoplastic drug mitomycin C in plasma and urine samples. Mitomycin is isolated from the biological matrix with the aid of a Sep-Pak C18 extraction column and eluted with methanol. The methanol is evaporated and the residue is redissolved in the chromatographic mobile phase (methanolic phosphate buffer). Mitomycin C is separated from coextracted compounds by reversed-phase liquid chromatography on a LiChrosorb RP-8 column. A high detection sensitivity and selectivity was obtained by photometric measurements at 365 nm. The precision of the determinations was better than 6% relative standard deviation for plasma samples within the range 2-1000 ng/ml, and for urine samples within the range 0.5-4.4 micrograms/ml. The pH-dependent stability of mitomycin in buffer solutions has been studied.