ANALYSIS OF OXYHALIDES IN WATER BY ION CHROMATOGRAPHY IONSPRAY MASS-SPECTROMETRY

A sensitive method for analyzing chlorite, chlorate, bromate and iodat e in water by ion chromatography (IC) coupled with ionspray tandem mas s spectrometry (IS-MS-MS) has been developed. Prior to analysis, sampl es were subjected to off-line sample clean-up with Ba, Ag and H-form r esins to remove sulfate, chloride and hydrogencarbonate, respectively. Oxyhalides in the purified samples were concentrated and separated cn a short, high-performance anion-exchange column. An eluent consisting of ammonium nitrate in methanol-water (9:1, v/v) was found to be suit able for separating the analytes, while providing enhanced detector se nsitivity. The coupling of IC with IS-MS-MS allows for the identificat ion of the four oxyhalides mentioned above in a single run with very h igh specificity and sensitivity. (C) 1998 Elsevier Science B.V.