Optimizing ion chromatography-inductively coupled plasma mass spectrometryfor speciation analysis of arsenic, chromium and bromine in water samples

Inductively coupled plasma mass spectrometry (ICP-MS) was coupled as a mult ielement detector for ion chromatography (IC) in analysis of chromium, arse nic and bromine species. The efforts were focused on selecting instrumental and operating conditions suitable for IC-ICP-MS. The choice of the eluent for IC was found to be critical. Ammonium buffer and nitric acid were suita ble eluents since they did not cause polyatomic interferences or salt depos ition on the cone orifices of ICP-MS. Cationic and anionic species could be analyzed simultaneously by coupled column IC-ICP-MS constructed by couplin g anion and cation columns in series. This system was applied for speciatio n of chromium. A method for simultaneous analysis of toxic arsenic and chro mium species was developed. Also an on-line preconcentration method allowin g extremely low detection limits for bromine species is introduced. By usin g 5 mL injection volumes bromate and bromide could be analyzed at 0.2 mug L -1 level.