Direct and simultaneous determination of molybdenum and vanadium in sea-water using a multielement electrothermal atomic absorption spectrometer

Abstract

Direct and simultaneous determinations of Mo and V in sea-water using a multi-element electrothermal atomic absorption spectrometer (Perkin-Elmer SIMAA 6000) are described. Three kinds of chemical modifier [Mg(NO₃)₂ , Pd(NO₃)₂ and a mixture of both] were tested. A simple calibration curve method could be used to determine Mo in sea-water using Pd or a mixture of Pd and Mg as the chemical modifier. A standard additions method was used to determine V and to determine Mo and V simultaneously in sea-water. The detection limits were 0.35–0.60 µg l^–1 for Mo. The detection limit for V in this work (0.32–0.51 µg l^–1) is much lower than those reported in the literature (18–50 µg l^–1), such that direct determination of V in unpolluted sea-water (<2 µg l^–1) by ETAAS is possible. The RSDs for the simultaneous determination of Mo and V in nearshore or open ocean sea-water are ≤11% using a mixture of Pd and Mg as the chemical modifier. The accuracy of the method for Mo determination was confirmed by the analysis of two kinds of certified reference sea-water. There is no certified value of V provided for these reference sea-water samples. The experimentally determined of V concentrations were compared with values reported in the literature.