建立了掺杂硒碳糊电极同时测定铜和铋的微分电位溶出法。在HCl(0.05mol/L)中,在-0.3V(vs.Ag/AgCl)下,Cu2+和Bi3+电沉积在电极表面,再在溶液中溶解氧的作用下,铜和铋从电极表面溶出,分别于0.30V和0.02V获得灵敏的电位溶出峰。微分电位溶出峰高(dr/dE)与铜和铋的浓度成线性关系,线性范围为5.0×10-9~1.55×10-7mol/L,检出限分别为4.0×10-9和2.5×10-9mol/L(S/N=3)。方法用于实际样品中铜和铋的测定,结果令人满意。
A differential potential stripping method based on employment of the selenium powder doped carbon paste electrode (Se/CPE) was established to simultaneously determine copper and bismuth. In the 0.05 mol/L HC1 solution, Cu2+ and Bi3+ were electrodeposited on the electrode surface at the applied po- tential of --0.3 V (vs. Ag/AgCl). Then copper and bismuth were stripped from the electrode surface due to oxidation reaction under the dissolved oxygen in the solution, which lead to generation of sensitive oxi- dation stripping peaks at 0.30 V and 0.02 V, respectively. Using this method, it was found that the peak heights of differential potential stripping peaks linear relationship with the concentrations of the copper and bismuth in the concentration range of 5.0× 10-9-1.55×10-7 mol/L. The determination limits of copper and bismuth were 4. 0×10-9 mol/L and 2.5×10-9 mol/L(S/N= 3), respectively. The procedure has been applied to simultaneously determine copper and bismuth in actual samples with satisfactory results.