Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Lublin, Poland.
Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Lublin, Poland.
Talanta. 2018 May 15;182:62-68. doi: 10.1016/j.talanta.2018.01.053. Epub 2018 Feb 20.
A bismuth film electrode prepared in situ with a reversibly deposited mediator (Zn) applied for ultrasensitive determination of Cr(VI) using differential pulse catalytic adsorptive stripping voltammetry is presented. The optimization of experimental conditions such as composition of the supporting electrolyte, potential and time of bismuth film formation as well as analyte accumulation, and DP mode parameters is reported. For 180 s accumulation time, very low limits of detection and quantification of Cr(VI) were obtained, with 5.8 × 10 and 1.9 × 10 mol L, respectively. The relative standard deviation for 5.0 × 10 mol L of Cr(VI) was 3.9% (n = 5). Finally, the proposed procedure was applied to determine Cr(VI) in the certified reference materials - NASS-6 (seawater), SLEW-3 (estuarine water) and TMRAIN-04 (rainwater) - as well as in river water samples. Furthermore, the obtained results show that the proposed voltammetric procedure employing the bismuth film electrode prepared with mediator appears to form a very promising tool for the speciation of chromium at ultratrace level.
本文提出了一种采用可逆沉积的媒介物（Zn）原位制备的铋膜电极，用于使用差分脉冲催化吸附溶出伏安法对 Cr(VI)进行超灵敏测定。报道了实验条件如支持电解质组成、铋膜形成的电位和时间以及分析物的积累和 DP 模式参数的优化。对于 180s 的积累时间，获得了非常低的 Cr(VI)检测限和定量限，分别为 5.8×10 和 1.9×10 mol·L。对于 5.0×10 mol·L 的 Cr(VI)，相对标准偏差为 3.9%（n=5）。最后，该方法应用于测定 NASS-6（海水）、SLEW-3（河口水）和 TMRAIN-04（雨水）等标准参考物质以及河水样品中的 Cr(VI)。此外，所得结果表明，采用媒介物制备铋膜电极的这种伏安法程序似乎为超痕量水平的铬形态分析提供了一种很有前途的工具。
