锑(Ⅲ)-棓酸配合物示差脉冲吸附溶出伏安法研究

Studies on the Differential Pulse Adsorptive Stripping Voltammetry of Antimony ( Ⅲ )-Gallic Acid Complex

本文在前文的基础上,进一步研究了锑(Ⅲ)-棓酸配合物在醋酸盐缓冲溶液中的示差脉冲吸附伏安特性,探讨了反应机理,用拟定的方法测定了铜合金中的痕量锑,结果满意。 1 实验 1.1 仪器和试剂 PAR 174A型极谱仪,303A型静汞滴电极,电极面积1.61 mm^2,文中所有电位均对Ag/AgCl电极测量;305型搅拌器;pHS-3B型酸度计。锑(Ⅲ)

In the 0. 10 mol/L acetate buffer solution with pH 4. 4, a sensitive reduction wave of antimony-gallic acid complex has been obtained at -0. 47 V (vs. Ag/AgCl) using differential pulse voltammetry. The peak current is linearly proportional to the concentration of antimony in the range of 4. 0×10-10 to 8. 0×10-8 mol/L after a 2 min accumulation. The reaction mechanism has been discussed. It is shown that the current is caused by the reductioin of antimony ( It ) bonded in the complex which is adsorbed on the hanging mercury drop electrode, and that the adsorption of the complex obeys Frumkin isotherm. The proposed method has been applied to the determination of trace antimony in copper alloys with satisfactory results.