On-Line Separation and Determination of Bromate in Drinking Waters

Oct 21, 2000 - A flow injection (FI) system with a microcolumn of anion exchanger has been used to effect rapid on-line separation of bromate and brom...
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Anal. Chem. 2000, 72, 5725-5730

On-Line Separation and Determination of Bromate in Drinking Waters Using Flow Injection ICP Mass Spectrometry* A. R. Elwaer,† C. W. McLeod,*,† and K. C. Thompson‡

Centre for Analytical Sciences, Department of Chemistry, University of Sheffield, Dainton Building, Sheffield, S3 7HF, U.K., and Alcontrol (UK) Ltd., Templeborough House, Mill Close, Rotherham, S60 1BZ, U.K.

A flow injection (FI) system with a microcolumn of anion exchanger has been used to effect rapid on-line separation of bromate and bromide prior to quantitation by ICP mass spectrometry. Basic performance studies are described including the effect of key FI parameters, i.e., sample injection volume, carrier stream flow rate, and eluent concentration on system response. The new approach permitted ultratrace determinations of bromate in drinking waters, the main benefits being low limit of detection (0.13 µg/L based on a 500-µL sample injection), rapid analysis time (10 min/sample), and good precision (2.8% at the 5 µg/L level). Accuracy was checked via an ECsponsored interlaboratory trial. Carcinogenic byproducts (e.g., trihalomethanes) may be generated as a result of utilizing chlorination for water purification, hence, the considerable interest in applying alternative treatments based on ozonolysis. Ozonation of bromate-containing waters, however, may result in formation of bromate, a possible human carcinogen.1,2 Studies have indicated that the concentrations of bromate in processed waters are dependent on several parameters including ozone dose and duration, temperature, pH, and indigenous concentration of bromide.3,4 In the study of Sacher et al.,4 for example, bromate concentrations reported for four waterworks ranged from