1. CE is shown as a tool for a more-dimensional identification of organic metal binding partners. Methods are given for a further improvement of the identification security of the organic ligands [1], when analyzing molecules of nearly equal mobility. CE is used here as a powerful tool for quality assurance and quality control in speciation investigations.2. Methods are presented for a direct separation and identification of different species. As an example, seleno organo compounds are separated from their sulphur analogues in model solutions and native samples. Standard addition methods [1, 2] as well as UV spectra of both species help to identify these molecules as seleno- or sulphur-organo compounds. Further methodological developments and separations are shown for Pt-compounds.