化学修饰碳糊电极三元铬合物体系测定天然水中痕量钴

Determination of Trace Cobalt in Natural Water by Ternary Complex System with Phenanthroline Chemically Modified Carbon Paste Electrode

研究了邻菲啉化学修饰碳糊电极，在含噻吩甲酰三氟丙酮的ＨＡｃ－ＮａＡｃ体系中，Ｃｏ（Ⅱ）离子经化学富集在电极表面上形成三元络合物。采用２．５次微分伏法测定痕量钴。Ｃｏ（Ⅱ）浓度在８．０×１０－９～７．０×１０－７ｍｏｌ·Ｌ－１范围内与阳极溶出峰峰高呈良好的线性关系，检出限达１．２×１０－９ｍｏｌ·Ｌ－１．电极用于水样中钴的测定，结果令人满意。

The preperation of phenanthroline chemically modified carbon psate electrode and electyochemical characteristics of the electrode in HAc-NaAc medium were described. Owing to the synergistic effect of HTTA, the ternary complex was formed on the electrode surface. Using2.5-order differential voltammetry and for a chemical preconcentration time of 7min ,the mothod showed goog linearly for 8.0×10 -9 to 7.0×10 -7 mol\5L -1 cobalt (Ⅱ). The deteclion limit is 10 -6 mol\5L -1 for cobalt. The recommended procedure can be used for the determination of trace amount of cobalt in natural water. [WT10.5,10.25HZ]