HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF CIS-DICHLORODIAMMINEPLATINUM(II) IN PLASMA ULTRAFILTRATE

A reproducible, simple and sensitive high-performance liquid chromatog raphic method was described for the quantitative analysis of cis-diamm inedichloroplatinum(II) (CDDP) in ultrafiltrate plasma in the presence of nickel chloride as internal standard. CDDP and the internal standa rd were chelated by exchange with diethyldithiocarbamate. After deriva tization, the mixture was directly injected into the column. Chromatog raphy was performed on an Ultrasphere column and the eluent measured s pectrophotometrically at 260 nm for CDDP and at 250 nm for the interna l standard. The peak area ratio of CDDP to the internal standard varie d linearly with concentration over the range 0.05-10 mu g ml(-1). Prec ision and reproducibility were both excellent and the limit of quantif ication was 0.03 mu g ml(-1) using only 0.5 mi of ultrafiltrate. The p resent method, without extraction, should be entirely automated. This assay may be suitable for therapeutic drug monitoring in patients rece iving CDDP.