Enhancing the sensitivity of potential step voltammetry using chemometric resolution.
Enhancing the sensitivity of potential step voltammetry using chemometric resolution.
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DOI：
10.1039/c3an01719b
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发表时间：
2014-02
期刊：
影响因子：
--
通讯作者：
Jiarun Tu;W. Cai;X. Shao
中科院分区：
文献类型：
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作者：
Jiarun Tu;W. Cai;X. Shao
通过改善信号质量来提高分析方法的灵敏度是分析化学的普遍目标。在分析电化学体系中，尽管在理论和实验上进行了大量的努力，但双电层充电电流一直是影响法拉第电流准确测量的一个障碍。本文提出了一种利用化学计量学分辨提高电位阶跃伏安法灵敏度的方法。利用三线性分解方法，直接从不同电位下测量的衰减曲线数据矩阵中提取净法拉第电流和双电层充电电流。利用模拟数据证明了该方法的可行性，并通过扩散和吸附控制反应的实验数据进一步验证了该方法的有效性。与在较晚的脉冲时间记录电流数据的常规方法相比，提取的净法拉第电流的伏安图是具有水平基线的理想S形曲线，即使对于非常低浓度的样品也是如此。更重要的是，当净法拉第电流用于定量测定时，可以大大提高分析灵敏度。
Enhancing the sensitivity of analytical methods by improving the signal quality is a universal goal in analytical chemistry. In analytical electrochemistry systems, the double layer charging current has been an obstacle to the accurate measurement of the faradaic current despite theoretical and experimental efforts. In this study, a method for sensitivity enhancement for potential step voltammetry is developed using chemometric resolution. Trilinear decomposition is used to extract the net faradaic current and double layer charging current directly from the data matrix of the decaying curves measured at different potentials. The feasibility of the method is proven using simulated data and further validated by two experimental datasets of diffusion and adsorption control reactions. Compared with the conventional approach that records the current data at a later pulse time, the voltammogram of the extracted net faradaic current is an ideal sigmoid curve with a horizontal baseline, even for the samples of very low concentration. More importantly, the analytical sensitivity can be greatly improved when the net faradaic current is used for quantitative determination.