Simultaneous multielement determination of hydride- and oxoanion-forming elements in seawater by inductively coupled plasma mass spectrometry after lanthanum coprecipitation

The simultaneous multielement determination of trace elements in seawater, especially hydride- and oxoanionforming elements, has been investigated by inductively coupled plasma mass spectrometry with the aid of lanthanum copr ecipitation preconcentration. The optimum pH in lanthanum coprecipitation w as pH 9.5; at this value, trace elements were well recovered and major cons tituents of seawater such as Na, Mg, K, and Ca were significantly reduced i n the concentrated solutions. The recovery values obtained for V, Cr(III), Mn, As(III), As(V), Se(IV), Y, Sn, Sb(III), Sb(V), W,Bi, and U were more th an 85% after lanthanum coprecipitation, while Cr(VI), Se(VI), and Mo(VI) pr ovided poor recoveries of less than 30%. The reproducibility for coprecipit ation was within 5% as relative standard deviation. The present method was applied to the determination of trace elements in coastal seawater referenc e material CASS-3. The analytical values for Mn, As, V, Y,Sb, W, and U were in fairly good agreement with the certified or literature values.