Use of the method of preliminary concentration for simultaneous neutron activation determination of Hg, Cd and Zn in natural waters

Studied are the possibilities of simultaneous determination of trace amounts of mercury, cadmium and zinc in natural waters. Developed is a method of neutron-activation analysis based on the preliminary concentration of elements being determined. Samples of various natural waters are analyzed. Samples of natural waters of the 100 ml volume are passed through the chromatographical column with resin in the H+-form with the rate of 1 ml/minxcm2, Hg, Cd, Zn being sorbed in the resin completely. The total desorption of mercury, cadmium and zinc traces has been carried out with the help of 0.1,1.3 and 3.0 M HNO3, respectively. After washing-out eluates of 2-5 ml have been soldered in quartz ampules and irradiated during 2 hours in the reactor channel by the flux of thermal neutrons of 1x1013 neutr/cm2xs. The sensibility of the method for Hg constitutes 4.5x10-12, for Cd - 1.6x10-10 and for Zn - 2.3x10-8 g/ml. The developed technique differs from the existing ones by simplicity, high sensitivity and higher efficiency