Studies On The Electrochemical Behaviors Of The Bismuthum, Osmium, Cobaltum And Its Application

The determination of trace elements play an important role in environmental science, medicine, food and clinic. Electrochemistry method has the advantages of quickness, convenience, sensitivity and not being interfered by the color of the solution, The electrochemical behaviors of bismuthum and osmiumand and cobaltum studied by polorgraphic method. The content and results are as follows: 1. Study on Catalytic Adsorptive Wave of Bi (HI) and Salicylaldoxime System and Its ApplicationThe electrochemical behaviors of Bi (III) and Salicylaldoxime system has been studied in polarographic method. In 0.025mol.L-1 NH3-NH4CI buffer solution at pH=8.0, a sensitive derivative polarographic of the Bi (III) and HSAO system appears at -0.82 V (vs.SCE) . The peak current is proportional to bismuth concentration in the range of 3.0 X 10-8mol L-1~5.0X 10-6mol L-1, the detection limit is 2.0X 10-8Vol.L-1. The molar ratio of Bi (III) to HSAO is 1:1. Several electrochemical methods have been used to study the properties of the polarographic wave and the mechanism of electrode. It is proved that the wave is a catalytic adsorptive one, the number of electrons transferred (n) is 3. The procedure is simple and quick .It also has higher sensitivity. The method has been successfully applied to the determination of trace bismuth in hair and compound bismuth aluminate.2. Study on the electrochemical behaviors of Os( IV )-Cysteamine hydrochloride-As (III) System and Its ApplicationBy use of single sweep polarography, a well-defined polarographic wave was observed for the Os(IV)-Cysteamine hydrochloride-As(III) System complex in 0.04 mol/L HC1-KC1 buffer solution at pH 1.8 .The sensitive second derivative polarographic wave of Os(IV)-Cysteamine hydrochloride-As(III) complex appears at -1.40V (vs.SCE) .The peak current is proportinonal to Os(IV) concentration inthe range of 0.50~95.0ng/mL, the detection limit is O.lOng/mL. This method hasbeen successfully applied to the determination of trace osmium in artifical sampleconcentrate of noble metaland secondary alloy.3. Study on Catalytic Adsorptive Wave of Co( II )-Neutral Red-NO2 and ItsApplicationIn 0.03 mol/L NH3-NH4CI buffer solution, at pH 8.5, a sensitive second derivative polarographic wave of Co( II )-Neutral Red-NCV complex appears at -1.19V (vs.SCE) .The peak current is proportinonal to Co( II) concentration in the range of 2.0X 10-8~5.0X10-6mol/L,the detection limit is 1.0X 10-8mol.L-1.Several electrochemical methods have been used to study the properties of the polarographic wave and the mechanism of electrode. It is proved that the wave is a catalytic adsorptive one. The peak current is produced by the reduction of Co( II ),The molar ratio of Co( II) to Neutral Red is 1:1, the number of electrons transferred (n) is 2. This method has been successfully applied to the determination of trace cobalt in vitamin B12 and water samples.