An Ion Chromatographic Method for Measuring <5 μg/L Bromate Ion in Drinking Water

Many laboratories using the best available technology (ion chromatography) can only reliably measure BrO3- at the 10-20 micrograms/L level. Typically, BrO3- peak resolution is not a problem; however, finished water can contain appreciable amounts of Cl- that can interfere with BrO3- measurement using conductivity detection. Chlorpromazine is a selective reagent that does not react with Cl- and is an ideal postcolumn detection chemistry following IC separation. The chlorpromazine postcolumn method is linear over the 0.5-100 micrograms/L range.