New suppressor technology improves the ion chromatographic determination of inorganic anions and disinfection by-products in drinking water

This paper describes a new suppressor technology for analyzing water samples using United States Environmental Protection Agency (EPA) methods 300.0 and 300.1. The Alltech DS-Plus suppressor improves and simplifies anion analysis in drinking water. In addition to suppressing the carbonate mobile phase and enhancing the analyte signal like conventional ion chromatography (IC) suppressors, the DS-Plus suppressor removes carbonic acid (as dissolved carbon dioxide) from the suppressor effluent before detection (US patent Nos.: 6 444 475; 6 468 804; others pending), lowering the background conductivity to near zero. Anions are detected in water background, improving sensitivity and lowering detection limits. The water-dip often seen with conventional suppressors is greatly reduced, improving fluoride quantification. The DS-Plus suppressor operates continuously without the need for external regenerants or switching valves. The performance of this new suppressor for analyzing water samples has been found to meet the EPA methods specifications.