Hyphenated techniques combine the separation power of ion chromatography (IC) with the detection power of a mass spectrometer.
This provides the sensitivity and selectivity necessary for monitoring potentially toxic substances with lowest maximum contaminant levels (MCLs).
Combining IC with an electospray ionisation mass spectrometer (ESI-MS) or an inductively coupled plasma mass spectrometer (ICP-MS) solves even complex separation problems while achieving high sensitivities and selectivities.
These hyphenated techniques provide valuable information for unambiguous peak identification and are less prone to matrix influences than IC with conductivity detection.
Bromate, a potential carcinogen, is generated by the oxidation of bromide traces during water disinfection by ozonisation.
Current regulations for drinking water and mineral water stipulate limits of 10 and three ppb, respectively.
As far as traces of perchlorate in drinking water are concerned, the US Environmental Protection Agency (US EPA) has recently developed an IC-ESI-MS method (EPA 332) with a detection limit in the sub-ppb range.
IC-ICP-MS can be used to determine chromium, arsenic and selenium with the advantage of being able to distinguish between different oxidation states and chemical forms of the three elements.
As different valence states of an element have different properties, individual concentrations of element containing species are, from the toxicological point of view, far more significant than total element concentrations.