Teixeira M F, Ramos L A, Almeida Neves E, Fatibello-Filho O
Departamento de Química, Universidade Federal de São Carlos, SP, Brazil.
Fresenius J Anal Chem. 2000 May;367(1):86-9. doi: 10.1007/s002160051604.
The construction and the application of a silica gel based carbon-epoxy indicator electrode for the potentiometric determination of acids and bases are described. The effect of composition of silica gel and carbon-epoxy, slope (mV/pH), linear response (pH range) and the use for acid-base titrations were investigated. The data obtained for the acid-base titrations were compared with those obtained using a glass electrode in the same conditions. The electrode showed a linear response in the pH 2 to 13 range with a slope of -40.5 +/- 0.4 mV/pH (at 25 degrees C) and a response time of less than 15 s. The lifetime of the electrode was higher than one year (over 6000 determinations) with a decrease of only 5% of the initial potentiometric response. The silica gel based carbon-epoxy electrode showed excellent results in the end-point indication potentiometric titrations in determination of acids and bases. The miniaturization of the proposed electrode for flow injection analysis was investigated.
描述了一种基于硅胶的碳-环氧指示电极的构建及其在酸碱电位测定中的应用。研究了硅胶和碳-环氧组成、斜率（mV/pH）、线性响应（pH范围）以及在酸碱滴定中的用途。将酸碱滴定获得的数据与在相同条件下使用玻璃电极获得的数据进行了比较。该电极在pH 2至13范围内呈线性响应，斜率为-40.5±0.4 mV/pH（25℃），响应时间小于15秒。电极寿命超过一年（超过6000次测定），初始电位响应仅下降5%。基于硅胶的碳-环氧电极在酸碱电位滴定终点指示测定中显示出优异的结果。研究了所提出的用于流动注射分析的电极的小型化。
