Introducing "Insertive Stripping Voltammetry": Electrochemical Determination of Sodium Ions Using an Iron(III) Phosphate-Modified Electrode.
Introducing "Insertive Stripping Voltammetry": Electrochemical Determination of Sodium Ions Using an Iron(III) Phosphate-Modified Electrode.
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DOI：
10.1021/acssensors.9b02343
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发表时间：
2020-01
期刊：
影响因子：
8.9
通讯作者：
A. Suherman;Mengjiang Lin;Bertold Rasche;R. Compton
中科院分区：
文献类型：
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作者：
A. Suherman;Mengjiang Lin;Bertold Rasche;R. Compton
引入了一种新型溶出伏安法，其中预浓缩步骤包括将离子插入固相，然后是通过线性扫描伏安法排出离子的定量步骤。具体而言，使用磷酸铁(III)修饰的玻碳电极以电化学方式测定水溶液和合成汗液中的钠离子浓度。电化学方法包括一个恒电位步骤，将相对于 SCE 的电位保持在 -0.5 V 100 秒，然后进行线性扫描伏安法。结果表明，800 °C 下的热预处理和球磨机机械预处理分别改善了磷酸铁 (III) 对 Na+ 的电化学响应。通过热重分析、扫描电子显微镜和粉末X射线衍射评估了所涉及的结构和形态变化。该传感器对 Li+ 和 K+ 表现出良好的选择性，并在 0.025 M 和 0.2 M Na+ 之间表现出线性响应。作为原理验证，传感器被用来确定合成汗液中的钠含量。
A new type of stripping voltammetry is introduced in which the pre-concentration step includes ion insertion into a solid phase followed by a quantification step in which the ion is expelled via linear sweep voltammetry. Specifically, sodium ion concentrations in both aqueous solution and synthetic sweat are electrochemically determined using iron(III) phosphate-modified glassy carbon electrodes. The electrochemical method consists of a potentiostatic step holding the potential of -0.5 V vs. SCE for 100 s, followed by linear sweep voltammetry. It is shown that a thermal and mechanical pre-treatment at 800 °C and with a ball mill, respectively improve the electrochemical response of the iron(III) phosphate towards Na+. The involved structural and morphological changes were assessed by thermogravimetric analysis, scanning electron microscopy and powder X-ray diffraction. The sensor exhibits a good selectivity towards Li+ and K+ and shows a linear response between 0.025 M and 0.2 M Na+. As a proof-of-principle the sensor was used to determine the sodium level in synthetic sweat.