Simultaneous determination of small organic and inorganic anions in environmental water samples by ion-exchange chromatography

Abstract

Anion-exchange chromatography at elevated pH values is the method of choice for the simultaneous determination of weak and strong low-molecular-mass organic and inorganic acids. These are important species found in the environment where most of them are formed and further degraded, particularly if microbial activities are involved. A step gradient procedure with a weak eluent such as borate on a low-capacity column was developed for the simultaneous one-run one-column determination of most of these types of components in environmental water samples. High selectivity and detection limits below 1 μM were achieved. Other yet unknown coelutions of 3-hydroxybutyrate with fluoride and 2-hydroxybutyrate with propionate were found. The different retention characteristics of a high-capacity column was used to obtain additional evidence to identify interfering components. These separation procedures were used to investigate fog, lake sediment pore water and rain after roof run-offs.