REVERSED-PHASE LIQUID-CHROMATOGRAPHIC SEPARATION OF PLATINUM(II) COMPLEXES OF METHIONINE-CONTAINING AND HISTIDINE-CONTAINING PEPTIDES USINGPERFLUORINATED CARBOXYLIC-ACIDS AS ION-PAIRING REAGENTS

Reversed-phase liquid chromatography with the perfluorinated carboxyli c acids trifluoroacetic acid, pentafluoropropanoic acid (PFP) and hept afluorobutyric acid as ion-pairing reagents provides a flexible system for both the analytical and semi-preparative separation of the produc ts of the reaction between [Pt(en)(H2O)(2)](2+) and methionine- and hi stidine-containing peptides. High selectivity can be achieved by varia tion of the chain length and concentration of the ion-pairing reagent for organic modifiers (methanol, acetonitrile, tetrahydrofuran) at con centrations in the range 0-20% (v/v). In general, employment of PFP (9 .5 mmol l(-1)) and acetonitrile (2-6%, v/v) leads to the best results. The retention behaviour of the peptide complexes is influenced by the ir charge, hydrophobicity and coordination mode.