Li Yi-Heng, Xie Hong-Qi, Zhou Fang-Qin
College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan, P.R. China.
Talanta. 2005 Jul 15;67(1):28-33. doi: 10.1016/j.talanta.2005.02.009. Epub 2005 Mar 20.
A sensitive and selective procedure for the determination of trace silver(I) at alizarin violet modified carbon paste electrode has been developed. Silver(I) was accumulated on the electrode surface via complex formation with modifier in 0.1mol/L acetate buffer (pH 5.2). After electrochemical reduction of silver(I) had been carried out, the reoxidation wave of silver(0) appeared at 0.05V (versus SCE) on scanning the potential in the positive direction in 0.1mol/L H(2)SO(4)+2.0x10(-4)mol/L KBr. For a preconcentration time of 3min, the detection limit is 1.0x10(-10)mol/L and the linear range is from 3.0x10(-10) to 1.2x10(-7)mol/L. Many coexisting metal ions have little or no effect on the determination of silver(I). The proposed method was applied to the determination of silver in waste water and zinc alloy samples with satisfactory results.
已开发出一种在茜素紫修饰碳糊电极上测定痕量银（I）的灵敏且选择性的方法。银（I）通过在0.1mol/L醋酸盐缓冲液（pH 5.2）中与修饰剂形成络合物而在电极表面富集。在对银（I）进行电化学还原后，在0.1mol/L H₂SO₄ + 2.0×10⁻⁴mol/L KBr中向正方向扫描电位时，银（0）的再氧化波出现在0.05V（相对于饱和甘汞电极）处。对于3分钟的预富集时间，检测限为1.0×10⁻¹⁰mol/L，线性范围为3.0×10⁻¹⁰至1.2×10⁻⁷mol/L。许多共存金属离子对银（I）的测定影响很小或没有影响。该方法应用于废水和锌合金样品中银的测定，结果令人满意。
