Retention behavior of an antitumor platinum complex cisplatin on ion exchangers.

Abstract

The novel aspects of Cisplatin, a potent antitumor platinum complex, on HPLC with ion exchange columns were studied. Although Cisplatin is an inorganic nonionic complex, it was retained on both anion and cation exchange columns, but not on reversed-phase columns. The capacity factor was larger on a column with higher ion exchange capacity; a capacity factor of more than 30 was obtained in a system composed of anion exchange MCI GEL CA 10S column and sodium dihydrogen phosphate eluent. However, the capacity factor measured on a column using the appropriate salt solution as the eluent was not affected by changing the concentration or pH of the eluent. The effect of UV absorptivity of an eluent on the peak height of Cisplatin was studied at various wavelengths in order to confirm the absence of an ion-exchange sorption mechanism in the eluent. No difference was observed between the relative peak height-detection wavelength profiles obtained with UV absorbing eluents and those obtained with UV-non absorbing eluents. These results indicated that Cisplatin might not be retained by ion exchange mechanism, but by other mechanisms such as ion-dipole interactions between Cisplatin and the functional groups of the stationary phases.