Determination of trace amounts of zinc in water samples by flow injection isotope dilution inductively coupled plasma mass spectrometry

Flow injection isotope dilution ICP-MS was applied to the determination of zinc in several water samples. A matrix separation and preconcentration system was used for the separation of Mg, Ca, S and Cl matrix and preconcentration of trace amounts of zinc in high salt content samples. A complete preconcentration cycle was accomplished in 4 min. The isotope ratio for each injection was calculated from the peak areas of the flow injection peaks. The precision for the isotope ratio determination was better than 1.7%. A detection limit of 0.014 ng ml(-1) was obtained for zinc with this method, The method was successfully applied to the determination of trace levels of zinc in SLRS-2 riverine water, SLEW-2 estuarine water, NASS-3 open ocean sea-water and CASS-3 nearshore sea-water reference samples.