Ionen-Chromatographie von Polyphosphaten und Phosphonaten

Summary

A phosphorus-specific detection system was developed for ion-chromatographic determinations of polyphosphates and phosphonates. After hydrolysing the phosphates or oxidative decomposition of the phosphonates, the resulting o-phosphate is converted to the yellow phosphorusvanadomolybdenum acid and is measured photometrically at 410 nm. Even complex matrices (e.g., washing powder) give very simple chromatograms by phosphorus-specific detection. Moreover, it enables the use of many different eluting agents. With a KCl/EDTA-eluens the resolving power is very high and the column life is considerably prolonged as compared to the commonly used HNO₃-eluens. Various examples of the separations of polyphosphates and phosphonates are shown and the retention times of some phosphonates are compiled.