Determination of bromide, bromate and other anions with ion chromatography and an inductively coupled plasma mass spectrometer as element-specific detector

An implementation of the Dionex IonPac AS12A analytical column with an element-specific ICP-MS detection is described for the simultaneous determination of halogen and oxyhalogen anions, sulfate, phosphate, selenite, selenate and arsenate. The chromatographic separation was achieved in less than 4 min with an aqueous 11 mM (NH4)(2)CO3 (pH 11.2, adjusted with aqueous ammonia) as eluent. Special emphasis was given to optimize the ICP-MS detection conditions for the reliable detection (RSD<50%) of bromate and bromide at a bromine concentration level of 1.0 mu g l(-1) with 50 mu l sample injection volume. In order to achieve the highest detector response for bromine species an ultrasonic nebulizer equipped with a membrane desolvator had to be employed. The detection limits (S/N=3, sample injection volume 50 mu l) obtained with the IC-ICP-MS after the optimization were 0.67 mu g l(-1) for BrO3-, 0.47 mu g l(-1) for Br-, 69 mu g l(-1) for ClO2-, 4 mu g l(-1) for Cl- 47 mu g l(-1) for ClO3-, 13 mu g l(-1) for SO42-, 36 mu g l(-1) for PO34-, 0.4 mu g l(-1) for SeO32-, 0.3 mu g l(-1) for SeO42-, and 0.4 mu g l(-1) for AsO43-. (C) 1999 Elsevier Science B.V. All rights reserved.