Determination of chloride and sulfate ions in high-purity water by capillary electrophoresis

摘要

A method is developed for the determination of chloride and sulfate ions in trace concentrations in high-purity water by capillary electrophoresis. A leading electrolyte based on chromate ions is used for indirect photometric determination. Electrokinetic sample injection is utilized. The internal standard method is used to improve reproducibility, and the conditions of sample injection with field amplification using an aqueous plug are optimized. The method is validated on samples of distilled, twice-distilled, and deionized water. The accuracy of the results of analysis was verified by the added-found method. The analytical range for chloride and sulfate ions is 1-50 mu g/L; the detection limit is 0.3 mu g/L. The duration of one analysis is 4-5 min.