| The adsorptive wave and catalytic wave in polarographic method has attracted considerable interest as a kind of sensitive polarographic method. The high sensitive adsorptive wave and catalytic wave of more than 50 kinds of elements concluding Pt, Rh, Ir in DC polarography and single-sweep polaro-graphy has been put forward and applied to the analysis of complex mineral. Because the apparatus of adsorptive wave and catalytic wave is simple, the method is sensitive, and the operation is convenient and quick, this method has been used widely. According to it, the electrochemical property of theadsorptive wave and catalytic wave produced by methylene blue, 2- (1,3,4-triazolyazo) -5-diethylcarboxyaminobenzoic acid, methylene green and otherorganic reagents reacting with tellurium, copper, tin respectively is discussedin this paper. The contents are as follows:1. The electrochemical characters of the ion complex of tellurium (IV) and methylene blue on mercury electrode have been studied. In H2SO4 medium, tellurium (IV) has a polarographic wave at - 0.82V (vs. SCE). When little amount of methylene blue was added, the sensitivity was improved greatly. A polarographic wave with a peak shape was observed in the corresponding potential in DC polarograghy. In the voltammogram, reductive peak appearded in both the reductive curve and the oxidative curve, which is the typical character of catalytic wave. The results of the experiments (the dependence of the polarographic current on the temperature, the electrocapiilary curves) prove that this catalytic wave has adsorptive character. It's observed that hydrogenseparated out in the mercury electrode. The contrast experiment of tellurium (0) is also done and according to the result, the possible reacting equationof the electrode process is given. The peak height of the wave is proportional to the concentration of Te (TV) from 4.0×10-9 to 1.0×10-7μg/L, and the detect limit is 6×10-10g/mL, and has been applied to the determination of tellurium in wheat flour.2. In PH 3.0 KHP-KNO3 medium, TZADCAB reacts with Cu (II) to produce a 1 : 2 complex. The polarographic wave is proved to be a complex adsorptive wave by the experiments of cyclic voltammetry, the electrocapillary curves, the polarographic current on the temprature and the accumulation time. The polarographic current is proportional to the concentration of Cu2+ from 4.0×10-7to 1.6×10-6mol/L, and the detect limit is 6×10-8mol/L. It has been used in the determination of Cu2+ in the samples of rice, soybean and medlar. The spectral experiments shows that TZADCAB-Cu (II) complex has a adsorption peak at 570nm, which can be used in the UV spectral analysis.3. In 0.05mol/L H2C2O4 +0.003% methylene green system, Sn (TV) has a sensitive polarographic wave in the mercury electrode. The electrochemical property of methylene green-Sn (IV) complex were studied by all kinds of electrochemical methods. To make clear the mechanism of the electrode reaction, the same experiments were carried out with Sn (II) as the replacementof Sn (TV), and the same polarographic wave was found at ?0.50V (vs. SCE). It proves that methylene green-Sn (IV) was first reducted to Sn (II)in the mercury electrode and then Sn (II) was reducted to Sn (0). Accordingto the result, the possible reacting equation of the electrode process is given. The peak height of the wave is proportional to the concentration of Sn (TV) from 3.0×10-8 to 5.0×10-5g/mL, and the detect limit is 8.2×10-9g/mL- ft hasbeen applied to the determination of trace tin in juices of canned fruits.
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