Study on the Separation of Trace Oxoanionsby Ion Chromatography
含氧阴离子的离子色谱法研究

It was the first time that bifunctional ( cation exchange/anion exchange) stationary phase was used for the analysis of trace oxoanions by ion chromatography. The influence of sodium phosphate concentration and eluent pH on their separations was studied. An eluent of 7.5 mmol/L Na 2HPO 4(pH 9.3) was found to be the most suitable for the analysis of SeO 3 2- ,HAsO 4 2- ,SeO 4 2- ,WO 4 2- ,MoO 4 2- ,GeO 3 2- and CrO 4 2- simultaneously. An eluent of 0.75 mmol/L Na 2HPO 4(pH 9.3) was found to be the most suitable for the analysis of IO 3 -,H 2AsO 3 -,BrO 3 -,NO 2 - and NO 3 - simultaneously. The detection wavelength was 204 nm. Four other anion separation columns (AS4A SC, AS9 SC, AS11 and PAX 500), which had different structures and properties, were compared to CS5A column. The separation mechanism was also studied.