Simplified column-switching technology for the determination of traces of anions in the presence of high concentrations of other anions

摘要

A binary eluent model was proposed to study the retention behavior of trace anions in the presence of high concentrations of co-eluent anions. According to this model, the effect of the matrix on the retention of trace anions can be suppressed by using a high-concentration eluent. Based on the model, a simplified 'heart-cut' column-switching technology was proposed, in which the column-switching time window can be determined directly by standard solution of the analyte. By using this technology, a detection limit of 50 mu g/l was obtained for nitrate in the presence of 5000 mg/l chloride and 250 mg/l sulfate. The effect of the matrix on the concentration efficiency of weak acid anions was studied according to the result of phosphate. The possibility of the determination of weak acid anion by the 'heart-cut' technology was also discussed. The technology has been applied fur the determination of nitrate in high salinity sea water, the spike recovery is in the range of 89.2-101.3%. (C) 2000 Elsevier Science B.V. All rights reserved.