Simultaneous Determination of Cl- and SO42- in 30% Sodium Bisulfite Solution Samples by Ion Chromatography

A novel method for simultaneous determination of Cl- and SO42- in 30% sodium bisulfite solution samples by ion chromatography was established. A sample was pretreated with triethanolamine (TEA) to prevent sulfite from becoming sulfate. The mixture solution of 1.5 mol/L Na2CO3-3.5 mol/L NaHCO3-10% (v/v) (CH3)(2)CO was used as eluent with a flow rate of 1.0 mL/min. The injection volume was 25 microL. The separation was performed on an IonPac AS14 column and detected by suppressed conductivity with external acid mode. Both Cl- and SO42- have good linearity in the ranges of 0.05 - 1.5 mg/L and 0.20 - 15 mg/L with correlation coefficients above 0.999 and the detection limits of Cl- and SO42- were 0.01 and 0.03 mg/L, respectively. The proposed method is simple and rapid and has been successfully applied to the analysis of 30% sodium bisulfite samples. The entire process of analysis is completed within 12 min.