DETERMINATION OF METALS AT PPB LEVELS BY THIN-FILM X-RAY-FLUORESCENCE SPECTROMETRY AFTER COPRECIPITATION WITH A MOLYBDENUM CARRIER COMPLEX

A method is described for the determination of iron, cobalt, nickel, copper, zinc, cadmium and lead in water at μg 1-1 levels, in which the metals are coprecipitated with a molybdenum-pyrrolidinedithiocarbamate carrier complex. The precipitate is collected as a thin film on a membrane filter (0.4-μm pore-size) and analysed directly by x-ray fluorescence spectrometry. Detection limits, for 100-ml water samples and counting times of 200 s per element, are 1 μg metal l-1 or lower. Total dissolved metal concentrations are obtained without boiling or u.v. irradiation of the water sample. The method is applicable to river and estuarine waters and is not affected by dissolved organic matter. © 1979.