SIMULTANEOUS DETERMINATION OF TRACE OXOANIONS USING ION CHROMATOGRAPHY WITH ULTRAVIOLET ABSORBENCY DETECTION

CS5A column had bifunctional (cation exchange / anion exchange) statio nary phase. It was the first time that CS5A column was used for the an alysis of trace oxoanions by ion chromatography. The influence of sodi um phosphate concentration, methanol concentration, and eluent pH on t heir separations were studied. An eluent of 7.5 mM Na2HPO4, pH 9.3 was found to be the most suitable for the analysis of SeO32- HAsO42- SeO4 2- WO42-. MoO42-. GeO32-, and Cro(4)(2-) simulanteously. An eluent of 0.75 mM Na2HPO4, pH 9.3 was found to be the most suitable for the anal ysis of IO3-, H2AsO3-, BrO3-, NO2-, and NO3- simulanteously. The detec tion method employed was selective and direct UV absorbance at 204 nm was utilized. Several other anion separation columns (AS11 A-SC column , AS9-SC column, AS11 column, and PAX 500 column), which had different structures and properties, were compared to CS5A column. Among them, CS5A column was the best choice.