title: Bromate assay in water by inductively coupled plasma mass spectrometry combined with solid-phase extraction cartridges.
abstract: Based on selective sorption of bromide, bromoacetic acids (BAA) and bromomethanes on solid-phase extraction (SPE) cartridges, a sensitive and convenient method was developed for the determination of bromate in waters by inductively coupled plasma mass spectrometry (ICP-MS). Dionex OnGuard Ag and reversed-phase (RP) cartridges were tested for retention characteristics for bromide, BAA and bromomethanes. When a sample acidified with nitric acid was passed through an RP cartridge, BAA and bromomethanes were retained, afterwards bromide was absorbed as a precipitate of silver bromide and bromate was unretained when the nearly neutral sample passed a combination of Ag and H cartridges. After SPE pretreatment the recovery of bromate was 96-106%, and bromide remaining in the aqueous phase was found to be less than 0.06 microg L(-1) when the original bromide concentrations were less than 5 mg L(-1). Effectiveness of stacked Ag and H cartridges in removing bromide from chloride-containing samples was also examined. Common cations and other anions did not interfere with bromate determination. The detection limit for bromate is 57 ng L(-1). This method has been applied to analyse waters from various sources, and the recovery of the spiked bromate was in the range of 92-107%.
authors.affiliation: Centre for Advanced Water Technology, Block 2, Unit 241, Innovation Centre (NTU), 18 Nanyang Drive, Singapore 637723, Singapore. QTCai@cawt.sui.com.sg
authors.forename: Qiantao
authors.initials: Q
authors.lastname: Cai
authors.forename: Zhong-Xian
authors.initials: ZX
authors.lastname: Guo
authors.forename: Chunhai
authors.initials: C
authors.lastname: Yu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhaoguang
authors.initials: Z
authors.lastname: Yang