Gao Z, Li P, Zhao Z
Department of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan, 475001, People's Republic of China.
Talanta. 1991 Oct;38(10):1177-84. doi: 10.1016/0039-9140(91)80240-z.
The utility of carbon-paste electrodes modified with 2,2'-bipyridyl and Nafion for the differential pulse voltammetric determination of iron(II) in aqueous medium is demonstrated. The method is based on formation of the 2,2'-bipyridyl complex of iron(II) and its accumulation by the Nafion. The differential pulse voltammetric response of the accumulated complex is used as the analytical signal. The response was evaluated with respect to carbon-paste composition, preconcentration time, pH, iron(II) concentration and other variables. A 3-min accumulation period permits measurement of iron(II) down to 10(-8)M, and a relative standard deviation of 3.8% for 2 x 10(-6)M iron(II). Rapid and convenient chemical renewal allows use of a single modified carbon-paste electrode in multiple analytical measurements over several days. The proposed procedure was applied to the determination of iron in certified standard reference materials and trace iron in natural waters.
证明了用2,2'-联吡啶和Nafion修饰的碳糊电极在水介质中差分脉冲伏安法测定铁(II)的实用性。该方法基于铁(II)的2,2'-联吡啶配合物的形成及其被Nafion的富集。富集配合物的差分脉冲伏安响应用作分析信号。针对碳糊组成、预富集时间、pH、铁(II)浓度和其他变量对响应进行了评估。3分钟的富集期允许测定低至10(-8)M的铁(II)，对于2×10(-6)M铁(II)，相对标准偏差为3.8%。快速便捷的化学更新允许在几天内多次分析测量中使用单个修饰碳糊电极。所提出的方法应用于标准参考物质中铁的测定以及天然水中痕量铁的测定。
