1996 Volume 12 Issue 6 Pages 953-957
A method for the determination of trace amounts of molybdenum at ng l-1 levels in rainwater and snow is described. Molybdenum is extracted into xylene as a complex of N-benzoyl-N-phenylhydroxylamine (BPA), and subsequently back- extracted into 100μl of nitric acid for a determination by graphite-furnace atomic absorption spectrometry (GFAAS). The extraction and micro-volume back-extraction allows molybdenum to be concentrated about 6000-fold. The back- extracted solution is suitable for the determination of molybdenum by GFAAS. The conditions of extraction and back- extraction, such as acidity, concentration of BPA, and amount of nitric acid, were investigated. The detection limit for molybdenum is 0.54ng l-1 based on a 1700-fold preconcentration. The application of this method to the determination of molybdenum in various samples of rain-water and snow is demonstrated.
