Separation of some platinum(II) complexes by ionic strength gradient on a solvent-generated ion-exchange sorbent.

The compatibility of ionic strength gradient with solvent-generated ion-exchange chromatography on an octadecylsilica sorbent was proven for a mobile phase containing octanesulphonate. Only a slight baseline shift was observed during the gradient of the phosphate buffer, even at 210 nm. An equilibration time of 3 min between the runs was sufficient to obtain retention times with a reproducibility better than 1%. The compounds separated were cisplatin, carboplatin and related neutral and cationic platinum(II) complexes, including transplatin and the aquation products of cisplatin.