Buleandră Mihaela, Voica Lavinia Georgiana, Popa Dana Elena, Badea Irinel Adriana, Iorgulescu Emilia Elena, Cheregi Mihaela Carmen
Department of Analytical Chemistry and Physical Chemistry, Faculty of Chemistry, University of Bucharest, Panduri Avenue 90-92, District 5, 050663 Bucharest, Romania.
Molecules. 2025 Jan 17;30(2):369. doi: 10.3390/molecules30020369.
This paper summarizes the main findings of a study which aimed to examine the electrochemical oxidation of homovanillic acid (HVA), the final metabolite of dopamine. A pencil graphite electrode (PGE) was used as working electrode and the measurements were performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The type and the composition of the graphite leads used as PGE, the pH of the supporting electrolyte, as well as the scan rates were optimized by CV. The analyte was irreversibly oxidized in Britton-Robinson buffer (BRB) solutions. The interpretation of the voltammetric signals and the correlation of the acquired information were the key to addressing the electrode process undergone by HVA at the PGE. The outcomes of the pH and scan rate studies led to the conclusion that two electrons and two protons were involved in the diffusion-controlled process. Using the PGE, a linear relationship between peak current and HVA concentration was obtained between 1.0 × 10 M and 5.0 × 10 M by DPV in BRB with pH 2.0. The detection limit of 3.84 × 10 M was calculated. The accuracy, the precision, and the selectivity of the quantitative method have successfully undergone evaluation. The practical application of the developed voltammetric method was checked by determining the HVA concentration in spiked plasma samples, yielding good recovery values.
本文总结了一项旨在研究多巴胺的最终代谢产物高香草酸（HVA）的电化学氧化的研究的主要发现。使用铅笔石墨电极（PGE）作为工作电极，并通过循环伏安法（CV）和差分脉冲伏安法（DPV）进行测量。通过CV对用作PGE的石墨电极的类型和组成、支持电解质的pH值以及扫描速率进行了优化。分析物在 Britton-Robinson缓冲液（BRB）溶液中发生不可逆氧化。伏安信号的解释以及所获取信息的相关性是解决HVA在PGE上所经历的电极过程的关键。pH值和扫描速率研究的结果得出结论，在扩散控制过程中有两个电子和两个质子参与。使用PGE，在pH为2.0的BRB中通过DPV在1.0×10⁻⁶ M至5.0×10⁻⁵ M之间获得了峰电流与HVA浓度之间的线性关系。计算出检测限为3.84×10⁻⁷ M。已成功评估了定量方法的准确性、精密度和选择性。通过测定加标血浆样品中的HVA浓度，检验了所开发伏安法的实际应用，得到了良好的回收率值。
