Simultaneous determination of inorganic anions and metal ions by suppressed ion chromatography

In this work the simultaneous determination of environmentally interesting inorganic anions (BrO3-, SeO32-, SeO42-, HAsO42-, WO42-, MoO42-, CrO42-) an d metal ions (Pb2+, Cd2+, Ni2+, Cu2+) precomplexed by EDTA. by suppressed i on chromatography has been optimized. Throughout the work, a latex-based st rong anion-exchange resin and carbonate buffer as eluent have been used. Th e study was performed in presence of anions that commonly occur in real sam ples (Cl-, NO3-, SO42-). Separation has been optimized studying the main el uent parameters that influence analyte retention, that is carbonate concent ration and pH. The method developed has been applied to the determination of the species p resent in a water sample of the river Po (Turin, Italy). In order to reduce analysis time, the effect of carbonate concentration and pH gradient elutions have been studied. The gradient elution allowed us sh orter chromatographic runs without the baseline drift that usually arises d uring gradient elutions. (C) 1999 Elsevier Science B.V. All rights reserved .