Feasibility study of the determination of selenium, antimony and arsenic in drinking and mineral water by ICP-OES using a dual-flow ultrasonic nebulizer and direct hydride generation

The feasibility of the use of the NOVA-2 dual-flow ultrasonic nebulizer for the determination of selenium, antimony and arsenic in drinking and mineral waters by direct hydride generation inductively coupled plasma-optical emission spectrometry (HG-ICP-OES) has been investigated. The acidic sample and the borohydride solution are mixed directly on the surface of a quartz oscillating plate converting liquids into aerosol at the entrance of the spray chamber. The analytical figures of merit for the multielement determination of selenium, antimony and arsenic were evaluated. Results showed that the analytical performance of the new system was superior to that of conventional nebulization systems as well as conventional continuous HG with gas-liquid separation, regarding the susceptibility to non-spectroscopic interferences produced by transition metals. Detection limits between 0.7 and 2.1 ng mL(-1) were achieved with ICP-OES detection. The precision of 10 replicate measurements at the 0.25 mg L-1 level was between 1.0 to 1.5% relative standard deviation. The utility of the system was demonstrated in the determination of selenium, antimony and arsenic in hard drinking water ERM-CA011a as well as selenium in mineral water samples. The advantages and limitations of this system, compared with existing techniques, are discussed.