Separation and preconcentration of trace amounts of several metals in magnesium metal and nitrate, with activated carbon as a collector.
A method is described for the preconcentration and determination of traces of Hg, Ag, Cu, Fe, In, Mn, Pb, and Zn present as impurities in magnesium metal (1 g) and nitrate (100 g). After the metal sample has been dissolved in nitric acid (or the salt in water) and the pH adjusted to 8.1-9 (except for preconcentration of Hg, when pH 3 is used), the solution is filtered through a 2-cm paper coated with 50 mg of activated carbon. The trace metals are quantitatively adsorbed on the activated carbon and separated from the matrix. The rest of the procedure has already been described. The detection limits for the analysis of 1 g of Mg and 100 g of Mg(NO(3))(2).6H(2)O are 0.03-1.3 ppm and 0.00031-0.013 ppm respectively, for all the trace metals except Hg. The limit is 0.00001(4) ppm for Hg in 100 g of Mg(NO(3))(2).6H(2)O. The coefficient of variation is 4-33%, depending on the trace metal.
Kimura
M
M
Department of Chemistry, Faculty of Science, Nara Women's University, Nara 630, Japan.
Egawa
S
S