AWWA JAW10797

This article describes a combination of analytical methods for the determination of oxidized chlorine species. The methodology relies on sequential amperometric or potentiometric titrations under conditions that cause chlorine dioxide, chlorine, chlorite, and chlorate to be differentiated. Either phenylarsine oxide or sodium thiosulfate can be used as the titrant. Sample pretreatment and pH adjustment are used to differentiate among the various chlorine species.The approach can be adapted to characterize either feed and product streams of chlorine dioxide generators or treated drinking water. The detection limits in drinking water are believed to be approximately 0.05, 0.02, 0.02, and 0.25 mg/L for chlorine dioxide, chlorine, chlorite, and chlorate, respectively. Includes 24 references, tables, figure.