The isotopic exchange rate of thiourea in hexa(thiourea) plumbous nitrate was determined at two different concentrations.
The results showed that the complex is unstable in the kinetic sense. The rate of exchange increases with increase of concentration
of the free ligand and also of the complex. Furthermore, the results indicated that an increase in temperature by 15°C does
not influence the rate to any significant degree.
Isotope exchange of copper/II/ between bis/resacetophenone phenylhydrazone/ copper/II/ complex and copper/II/ in trin-butyl phosphate and methanol medium was studied. The experiments were carried out at different temperatures varying the concentration of both metal ion and the complex. The results show that the complex is kinetically labile. An increase in temperature increases the rate of isotope exchange. The increase in concentration also results in the enhancement of the rate of reaction.
Cadmium in water was preconcentrated by adsorption on activated carbon after complexation with potassium ethyl xanthate. The recovery was >90% in the concentration range 10 g l–1 to 500 g l–1 with an enrichment factor of 1000. The method was employed for the analysis of cadmium in spiked water samples, by NAA and AAS. The standard deviation and relative mean error was 0.062 and 0.015, respectively.
The isotope exchange behavior of thiourea with bis(thiourea)mercury(II) complex has been studied. The concentrations of both the metal ion and the complex were varied. The results show that the complex is labile in the kinetic sense. An increase in concentration increases the rate of exchange. Increase in temperature also results in an increase of the rate of exchange.
Silver from aqueous solution was preconcentrated by adsorption on activated carbon as silver xanthate. Factors influencing the adsorption of silver have been studied. Optimum conditions for the preconcentration of silver have been established.
Metal exchange behaviour of tris/diethyl dithiocarbamate/ chromium/III/ complex has been studied at 25°C and 35°C varying the concentration of the metal ion and the complex. Experimental observation showed that the complex is kinetically labile. Temperature and concentration increase, increases the rate of reaction.
Isotope exchange behaviour of bis/diethyl dithiocarbamate/ copper/II/ complex has been studied at 30 °C and 40 °C varying the concentration of the complex and metal ion. Results indicate that the complex is labile in chloroform dimethyl sulphoxide medium. Increase in concentration has significant effect on the rate of the reaction. Similarly the increase in temperature increased the rate of the reaction.
Isotopic exchange behaviour of bis(resacetophenone oxime) nickel(II) complex with nickel(II) in tri-n-butyl phosphate (TBP) and ethanol medium has been studied. The studies were carried out at different temperatures by varying the concentrations of both metal ion and the complex. Experimental observations showed that the complex is kinetically labile. Increase in temperature increases the isotopic exchange rate. Increase in concentration of either metal ion or complex results in significant increase of the reaction rate.
Authors:P. Devi, P. Rao, K. Seshaiah, and G. Naidu
Isotope exchange behaviour of bis/diethyl dithio carbamate/cadmium/II/ complex has been studied at 25°C and 35°C varying the concentrations of both metal ion and the complex. The results show that the complex is kinetically labile and the concentration has a significant effect on the rate of the reaction. Increase in temperature also effects the rate of exchange.
Authors:G. Naidu, N. Trautmann, S. Zaunar, T. Balaji, and K. Rao
The results of an instrumental neutron activation analysis of some elemental concentrations in different soil samples near the industrial areas at Tirupati, India, are reported. Altogether 14 elements, Sm, La, Cr, Co, Zn, Cs, Ce, Th, Rb, Na, K, Sr, Fe and Eu were determined. The samples were irradiated with neutrons at the 100 kW Triga - Mainz research reactor and the induced activities were measured by gamma-ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector in connection with a multichannel analyzer. The results are discussed.