Method based on Chelex-100 ion-exchange resin for the removal of chlorine interference in the determination of chlorite ion

✍ Scribed by Arun K. Bhindi; Barry Chiswell

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 931 KB
• Volume: 265
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(92)85162-y

✦ Synopsis

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A simple, inexpensive method for the removal of chlorine interference in the detennmatlon of chlorite ions m potable water 1s described The method IS based on the ability of an Ion-exchange resin (Chelex-100) to react with chlorine but not with chlonte Ion when mixtures of the two species are passed down a colunm containing the resin The method was found to be accurate for chlorite concentrations m the range 0 08-13 0 mg 1-l m the presence of at least a four-fold excess of chlorme (whether present as chlorine or chloramme) and the sample system used wdl remove chlorine concentrations of at least 6 mg 1-l Attempts to regenerate the used Chelex-100 by removal of the chlonne proved unsuccessful The method was successfully applied m tnals at a water treatment plant Keywords Ion exchange, Polarography, Chelex-100, Chlorme, Chlorite, Water TABLE 1 Rates of reactlon of oxychlorme species wth selected maskmg reagents [l] Speaes Oxahc acid Malonate Thloacetamlde Chlonne dloxlde Very slow Very slow Fast Chlorite Ion No reactlon Very slow Very slow Chlorate ion No reactnon No reactlon No reaction Hypochlorous acid Fast Slow Fast Chlorme Fast Very slow Fast