Department of Chemistry, Physical and Theoretical Chemistry Laboratory , Oxford University , South Parks Road , Oxford OX1 3QZ , U.K.
ACS Sens. 2020 Feb 28;5(2):519-526. doi: 10.1021/acssensors.9b02343. Epub 2020 Feb 11.
A new type of stripping voltammetry is introduced, in which the preconcentration 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 saturated calomel electrode (SCE) for 100 s, followed by linear sweep voltammetry. It is shown that a thermal and mechanical pretreatment at 800 °C and with a ball mill, respectively, improve the electrochemical response of the iron(III) phosphate toward 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 toward Li and K and shows a linear response between 0.025 and 0.2 M Na. As a proof-of-principle, the sensor was used to determine the sodium level in synthetic sweat.
介绍了一种新型的剥离伏安法，其中预浓缩步骤包括离子插入固相，然后通过线性扫描伏安法进行定量步骤，将离子排出。具体来说，使用磷酸铁修饰的玻碳电极电化学测定水溶液和合成汗液中的钠离子浓度。电化学方法包括恒电位步骤，将电位保持在-0.5 V 相对于饱和甘汞电极（SCE）100 s，然后进行线性扫描伏安法。结果表明，分别在 800°C 下进行热和机械预处理并用球磨机处理，可以改善铁（III）磷酸盐对 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 具有良好的选择性，并且在 0.025 和 0.2 M Na 之间表现出线性响应。作为原理验证，该传感器用于测定合成汗液中的钠水平。
