The determination of transition metals by ion chromatography is possible with direct conductivity detection (see AN-C-137) as well as with UV/VIS detection after post-column reaction. Here, the cations are separated as anionic complexes and analyzed after post-column reaction with PAR with subsequent UV/VIS detection. Speciation determination of iron (separation of Fe(II) and Fe(III)) is possible with this procedure. For trace analysis, Metrohm Inline Preconcentration Technique (MiPCT) is applied.