Ion-exchange HPLC method for the purity control of potassium trichloroammineplatinate (II) (KTCAP, CAS 13820-91-2), a key intermediate in the synthesis of novel platinum anticancer drugs. The analysis uses an ARION(R) SAX column, 5 um, 250 mm x 4.6 mm, part number ARI-5806-LM46, with isocratic elution by a phosphate buffer (0.05 M ammonium dihydrogen phosphate, 2% KCl, pH 3.0). Flow rate 1.0 ml/min, temperature 30 C, injection volume 5.0 ul, UV detection at 213 nm. Seven peaks are assigned: 1 KTCAP-aquacomplex, 2-4 unknown impurities, 5 KTCAP (main peak), 6 unknown impurity and 7 K2PtCl4. The note shows two chromatograms, the sample on the ARION(R) column and a test mixture on a Phenosphere column, and a "Main peak characteristics" table comparing both phases: ARION(R) SAX gives…