摘要
本文以汞膜电极于NH_4Cl介质(pH5.0)中,研究了钢铁试剂存在下,痕量铟的差分脉冲吸附溶出伏安行为,并探讨了吸附机理。发现在较负电位下(-1.5V)子富集后,所得阴极溶出峰更敏锐。铟浓度在1.0×10^(-10)～5.0×10^(-7)mol·dm^(-3)间有良好的线性,富集15min,检测限为4.0×10^(-11)mol·dm^(-3)。方法标准偏差及变动系数分别为0.064和8.4％。
The differential pulse adsorptive stripping voltammetric behaviour of the indium-Hcup system on the mercury-film electrode was investiga ted in NH4 CJ (pH 5.0) medium. Also, the mechanism of adsorptive accumulation was discussed. It was found that the retuction peak obtained was more sensitive by a preconcentration step at a more negative potential ( -1.50V, vs.SCE). The indium concentration over the range of 1.0×10-10-5.0×10-7mol·dm-3 was in good linear relationship with the peak current. Its detection limit was 4.0×10-12 mol·dm-3 after preconcentrating for 15 min. The standard deviation and variance coefficient of this method were 0.064 and 8.4% respectively.
