Voltammetric Peak Separation of Dopamine from Uric Acid in the Presence of Ascorbic Acid at Greater Than Ambient Solution Temperatures

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• 作者：Jyh-Myng Zen ; Cheng-Teng Hsu ; Yi-Lan Hsu ; Jun-Wei Sue ; and Eric D. Conte
• 刊名：Analytical Chemistry
• 出版年：2004
• 出版时间：July 15, 2004
• 年：2004
• 卷：76
• 期：14
• 页码：4251 - 4255
• 全文大小：105K
• 年卷期：v.76,no.14(July 15, 2004)
• ISSN：1520-6882

文摘

Peak overlap in voltammetry poses challenges for thequantitative analysis of electroactive species. Dopamineand uric acid are typically challenging to determinevoltammetrically because of their very similar oxidationpeak potentials. We report preliminary results of the useof a screen-printed carbon electrode for the determinationof dopamine and uric acid in an electrolyte solutionmaintained above ambient temperatures. Higher temperatures resulted in dramatic shifting of the dopamineoxidation peak toward lower potentials, while the uric acidpeak was essentially stationary. Ascorbic acid, an interference in voltammetric uric acid determinations, is effectively suppressed at higher temperatures. This resultedin a greater peak separation of dopamine from uric acidat higher temperatures, which is desirable for better peakintegration. In addition, greater current responses for bothspecies were recorded at higher temperatures. The causefor such an increase in peak current is unraveled usingac impedance measurements. Presented are preliminaryresults for determining dopamine and uric acid at temperatures higher than ambient. Much improved voltammetric peak separation and sensitivity is obtained at thesehigher temperatures compared to ambient.