Simultaneous determination of chlorite, chlorate, perchlorate and bromate in ozonated saline by using IC-MS

Abstract

A simple, accurate and reliable analytical method for simultaneous determination of chlorite, chlorate, perchlorate and bromate in ozonated saline by using ion chromatography coupled with triple quadrupole mass spectrometry (IC-MS) has been developed. The use of silver (Ag) and hydrogen (H) OnGuard cartridges and 100-fold dilution were found to be simple and effective for sample pretreatment. Under optimized MS parameters, method validation was convincingly confirmed. A good linearity was obtained with regression correlation coefficients (R²) larger than 0.999. The mean relative recoveries of chlorite (ClO₂⁻), chlorate (ClO₃⁻), perchlorate (ClO₄⁻), and bromate (BrO₃⁻) ranged from 79.96 to 97.63%. The obtained limit of detection (LOD) was 1.00 μg L⁻¹ for ClO₂⁻, 0.10 μg L⁻¹ for ClO₃⁻, 0.04 μg L⁻¹ for ClO₄⁻, and 0.50 μg L⁻¹ for BrO₃⁻. Chlorate and bromate were only detected in ozonated samples. In addition, the concentration of chlorate and bromate was in direct proportion to the amount of ozone in saline.