Department of Chemistry, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
Anal Bioanal Chem. 2013 Apr;405(11):3593-602. doi: 10.1007/s00216-013-6762-z. Epub 2013 Feb 14.
A new long-optical-pathway spectroelectrochemical cell for absorptometric measurements in the UV-Vis region was developed. This cell consists of two optical fibers brought face to face and fixed on the working electrode support. As a proof of concept, the spectroelectrochemical cell was applied to the determination of catechol using a press-transferred single-walled carbon nanotube film as the working electrode. Voltabsorptometry was demonstrated to be very helpful in understanding the mechanism of catechol oxidation. The experiments showed that the main oxidation product is o-benzoquinone, but other soluble side products are also observed. Multivariate calibration explains the selection of 390 nm as the best wavelength for the univariate absorptometric determination of catechol, avoiding the interference of oxidation side products. Catechol was quantified using both the electrochemical and the spectroscopic signal, demonstrating that this hybrid technique is an autovalidated analytical method. Dual detection of catechol was also carried out using amperometric spectroelectrochemistry. Finally, spectroelectrochemistry was used to quantify catechol in the presence of hydroquinone.
一种用于紫外可见区域吸光光度测量的新型长光程光谱电化学池被开发出来。该池由两根光纤面对面放置并固定在工作电极支架上组成。作为概念验证，该光谱电化学池被应用于使用压转移的单壁碳纳米管薄膜作为工作电极测定儿茶酚。伏安吸光光度法被证明对理解儿茶酚氧化机制非常有帮助。实验表明，主要的氧化产物是邻苯醌，但也观察到其他可溶性副产物。多元校准解释了选择 390nm 作为儿茶酚单变量吸光光度法测定的最佳波长，避免了氧化副产物的干扰。儿茶酚的电化学和光谱信号都被定量，证明了这种混合技术是一种自验证的分析方法。采用安培光谱电化学法对儿茶酚进行了双重检测。最后，利用光谱电化学法在存在对苯二酚的情况下定量测定儿茶酚。
