ONLINE METHOD FOR THE ANALYSIS OF SEA-WATER FOR TRACE-ELEMENTS BY INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY

A commercially available chelation concentration system for the on-line preconcentration of trace metals from saline solutions was modified to permit the simultaneous determination of Fe, Mn, Co, Ni, Cu, Zn, Cd and Pb in 5 ml sea-water samples in less than 10 min by inductively coupled plasma mass spectrometry. Modifications were necessary in order to obtain acceptably low blanks for several elements. The system was operated both with columns provided by the manufacturer and with columns containing silica-immobilized 8-hydroxyquinoline. Detection limits in sea-water ranged from 1.6 ng l-1 (for Pb) to 55 ng l-1 (for Ni) for the former columns, and from 0.3 ng l-1 (for Cd) to 47 ng l-1 (for Fe) for the latter. Accurate analyses of coastal and open-ocean sea-water certified reference materials were achieved with at least one of the column types for all elements except Fe and Co.