DIRECT DETERMINATION OF TRACES OF MOLYBDENUM IN SYNTHETIC SEA-WATER BY ATOMIC-ABSORPTION SPECTROMETRY WITH ELECTROTHERMAL ATOMIZATION AND SELECTIVE VOLATILIZATION OF THE SALT MATRIX

A simple and rapid method is described for the direct determination by graphite-furnace atomic absorption spectrometry (HGA-2100) of traces of molybdenum (O.1-4 ng) in synthetic sea water. It is shown that the salt matrix can be removed completely by selective volatilization at 1700-1850°C, but the original presence of NaCl, Na2SO4, and KCl causes a considerable decrease in molybdenum absorbance, and MgCl2 and CaCl2 a pronounced enhancement. The presence of MgCl2 prevents the depressive effects. Samples of less than 50 μl can be analyzed directly without using a background corrector, with a precision of<10%. © 1979.