A new method of analysis of peroxydisulfate using ion chromatography and its application to the simultaneous determination of peroxydisulfate and other common inorganic ions in a peroxydisulfate matrix

A new method for the determination of peroxydisulfate using ion chromatography has been developed. Elution of peroxydisulfate was effected by isocratic elution using 200 mM NaOH at 40 °C. A modification of the method using gradient elution was able to simultaneously determine other common inorganic ions (nitrate, nitrite, sulfate and chloride) down to significantly low concentrations in a peroxydisulfate matrix. The relative standard deviations (RSD) were in the range of 0.5–5%, for peak areas and <0.2% for peak retention times. The recoveries were between 95% and 120% for a concentration range of about 0.5–42 ppm. The limit of detection for peroxydisulfate ion was 0.2 ppm and for the other ions were ≤2 × 10−2 ppm. The calibration curves were linear with slope and intercepts close to 1 and 0, respectively.