DETERMINATION OF TRACE-ELEMENTS IN CERTIF IED RIVER WATER REFERENCE MATERIALS (JAC-0031 AND JAC-0032) BY ICP-MS

We participated in a joint experiment to certify the trace element con centrations in river water organized by the Japan Society for Analytic al Chemistry. The major and trace dissolved elements (Mg, Al, Mn, Ni, Cu, Zn, As, Cd, Pb) in river water reference materials (JAC 0031 and J AC 0032) were determined by inductively coupled plasma mass spectromet ry (ICP-MS). In an unspiked sample (JAC 0031) the concentration of Mg was slightly lower than the certified value obtained by this joint exp eriment. The zinc concentration was slightly higher than the certified value. In a spiked sample (JAC 0032), the concentrations of Mg and Mn were lower than the certified value. Zinc was again higher than the c ertified value. For the other elements, our values agreed very well wi th the certified values for both samples.