J. Phys. IV France
Volume 107, May 2003
Page(s) 945 - 948

J. Phys. IV France
107 (2003) 945
DOI: 10.1051/jp4:20030454

Pre-concentration of selected trace elements from seawater by co-precipitation on Mg(OH) $\mathsf{_2}$

P.M. Nicolaysen, E. Steinnes and T.E. Sjobakk

Department of Chemistry, Norwegian University of Science and Technology, 7491 Trondheim, Norway

Taking advantage of the natural content of Mg in seawater many trace elements can be separated by coprecipitation on Mg(OH) 2. This allows separation from interfering matrix elements and substantial improvement of the detection power. The separation was carried out at pH 10 by by adding NaOH to the seawater sample. After filtration the Mg(OH) 2 precipitate was dissolved in dilute HNO 3, and the solution was analysed by sector field ICP-MS. Mean values in seawater collected from 35m and 100m depths in the Trondheimsfjord, central Norway, are presented for the following l8 elements: V, Cr, Mn, Fe, Co, Ni, Cu, As, Y, Mo, Cd, Sb, Ce, Pr, W, Pb, Th and U. The reproducibility was generally 20% or better for most of the elements.

© EDP Sciences 2003