控制电位滴定法的误差分析

Errors Analysis on Controlled Potential Titration

研究了影响控制电位滴定法测定结果准确度的因素,得到的结论是:第一,电位的控制误差及滴定剂体积的测定误差是影响控制电位滴定法测定结果准确度的主要因素。计算模型中的比例系数越大,滴定曲线的变化率越大,这种影响越小。第二,多组分体系的测定误差,与组分在计算模型中比例系数的相对大小有关。比例系数越大,测定误差越小。第三,不同浓度(或不同浓度比)待测溶液滴定曲线的差异越大,对控制电位滴定法的测定越有利。

The factors affecting on the accuracy of controlled potential titration have been studied and some conclusions have been made. Firstly, the main factors which affect the accuracy controlled potential titration are the errors of the potential control and those of the titrant volume. And the bigger the proportionality coefficient in the calculative model and the sharper the change rate of the titration curve are, the less effects on the determination are. Secondly, in the multi-component system, the determination errors are related to the relative magnitude of the coefficients in the calculative model and the bigger they are, the less the determination errors are. Thirdly, the difference between titration curves of different concentration（or different concentration ratio） solutions is benefit for controlled potential titration.