Capabilities of microbore columns coupled to inductively coupled plasma mass spectrometry in speciation of arsenic and selenium

The performance of microHPLC-microconcentric nebulizer-inductively coupled plasma-mass spectrometry (ICP-MS) coupling for the simultaneous determination of As(III), As(V), monomethylarsenic acid (MMA), dimethylarsinic acid (DMA), selenite (SeIV) and selenate (SeVI) in water was evaluated. The accurate reduction of the off-column dead volume, specially the capillary of the micronebulizer, as well as the optimization of chromatographic conditions led to the claimed advantages expected for microbore columns: a significant diminution of sample and solvent consumption without sacrificing sensitivity and the overall resolution in faster analysis time (less than 5 min). Detection limits are in the range 0.03-0.04 μg L−1 for arsenic species and 0.35 μg L−1 for selenium species. The developed method was validated by analysing different spiked environmental water samples. Linearity, tested up to 50 μg L−1, showed correlation coefficients above 0.999 and no matrix effect for high saline water samples. Good accuracy and repeatability was obtained for spiked influent and effluent water treatment plant.