Determination Of Ru,Pt,Rh In Geological Samples By Oscillolarography After Separation And Entrichement By CAS Forming Resin

A new chelate-forming resin bearing CAS was prepared by stirring a solution of CAS with a macroporous strong basic anion exchange resin D290. The adsorption property and the optimal conditions on the adsorption and elution of noble metal were particularly studied. And determination of Ru, Pt,Rh by Oscillopolarography was established.Various parameters such as pH, height of column, flow rate of sample solution, eluent type, volume and flow rate of eluent were detailedly investigated. The results show that when the pH (HCl) is 1.00, column is longer than 8.0 cm. the flow rate of sample solution is lower than or equal to 1.0 mL/min and elution rate with 0.1 mol/L HCl-3% thiourea (40mL) is lower than or equal to 0.6 mL/min, Ru, Pt, Rh can be quantitatively preconcentrated. The recoveries determined by Oscillopolarography are satisfactory. It was proved that the stability and adsorption capacity of this forming resin with CAS were good, and it can be used repeatedly after adding a certain quantity of eluent:The optimal supporting electrolyte of testing by Oscillopolarography were investigated. It was found that Ru formed an electroactive complex with 2.5 mol·L-1 HCl—0.01% RB produced a catalytic wave with a peak at-1050 mV (vs sce), and Pt, Rh with 0.75 mol/L H2SO4—1.25×10-3mol/L (CH2)6N4—1.2% NH4Cl—0.003% N2H4·H2SO4 produced the catalytic wave with the peak at -1035 mV (vs sce). -1230 mV (vs sce).The results obtained by the analysis of standard sample (72-Pt-02) under the optimum conditions are satisfactory, the RSD:Ru:1.704%, Pt:0.760%, Rh:2.531%, and the vales of tcalculated:Ru:0.668, Pt:0.639, Rh:0.408. less than Ttable(0.05,7)=2.37. The detection limits:Ru:2.07×10-5μg·mL-1, Pt:5.15×10-6μg·mL-1, Rh:5.71×10-7μg·mL-1.This method is proved to be practical and efficient by practice. The main advantages are its simplicity, high speed and precision. It can be used to not only the analysis of geological samples, but also the water samples, environmental samples, and anti-cancer drugs.