基于伏安型离子选择性电极的pH检测研究

Study on pH determination based on voltammetric ion-selective electrode

将含有电活性物质的离子选择性膜直接滴涂在玻碳电极上,制成一种新型伏安型离子选择性电极(VISE)。通过在电极上施加循环伏安信号,提取电活性物质的还原峰电位可实现待测离子的定量分析。将这种VISE应用于pH检测,分别考察VISE的pH响应特性、离子选择性、实际样检测能力以及对积累电荷的抗干扰能力。结果表明:基于循环伏安法的VISE在pH检测中具有较好的准确性、灵敏度、重复性和离子选择性,可用于实际样品的检测。相比于基于电位分析法的传统离子选择性电极(ISE),可不受电荷积累的影响,在水质的实时在线监测中具有较好的应用前景。

A vohammetric ion-selective electrode （VISE） has been fabricated by using an ionselective membrane with electroactive species modified on a glassy carbon electrode. The reduction peak of electroactive species can be collected for quantitation by cyclic voltammetry. Employing this VISE for pH detection, its pH response characteristic, ion selectivity, real sample detectability and capacity of resisting charging accumulation interference have been investigated. The result shows that, this VISE own good accuracy, sensitivity, reproducibility and selectivity which can be employed on real sample detection. Comparing with conventional ion-selective electrode based on potentiometry, it cannot be influenced by charging accumulation interference, which turns out more promising for on-line water quality monitor.