FAST-SCAN VOLTAMMETRY OF BIOGENIC-AMINES
FAST-SCAN VOLTAMMETRY OF BIOGENIC-AMINES
复制标题
DOI：
10.1021/ac00164a006
复制
发表时间：
1988-07-01
影响因子：
7.4
通讯作者：
WIGHTMAN, RM
中科院分区：
文献类型：
--
作者：
BAUR, JE;KRISTENSEN, EW;WIGHTMAN, RM
探索使用快速扫描循环伏安法作为检测生物胺的分析技术。在有或没有全氟化离子交换材料涂层的碳纤维电极上以 200 V s-1 的扫描速率记录循环伏安图。在流动注射装置中记录伏安图，并使用背景扣除来去除残余电流。在未涂覆的电极上 4-甲基儿茶酚氧化的伏安图具有先前发表的儿茶酚在中等 pH 值下的氧化机制所预期的峰值幅度。相反，多巴胺、二羟基苄胺和去甲肾上腺素的伏安图显示出更大的峰值电流。这些伏安图的半积分给出了指示吸附的峰形曲线。在涂层电极上，阴离子物质的伏安图大大衰减，而对于生物胺，峰值电流比未涂层电极大。快速扫描伏安法对于 5-羟色胺的测定特别有利。较短的电解时间可以防止氧化产物在电极上形成绝缘膜。尽管这些化合物的吸附以还原形式发生，但该特征是有利的，因为它增加了信噪比。由于电极表面上的预富集，可以实现亚微摩尔检测限。
The use of fast-scan cyclic voltammetry is explored as an analytical technique for the detection of biogenic amines. Cyclic voltammograms were recorded at a scan rate of 200 V s-1 at carbon-fiber electrodes with and without coating of a perfluorinated ion-exchange material. Voltammograms were recorded in a flow injection apparatus, and background subtraction was used to remove the residual current. Voltammograms for the oxidation of 4-methylcatechol at uncoated electrodes had the peak amplitude expected for the previously published oxidation mechanism for catechols at intermediate pH. In contrast, voltammograms for dopamine, dihydroxybenzylamine, and norepinephrine showed much larger peak currents. Semiintegration of these voltammograms gives a peak-shaped curve indicative of adsorption. At coated electrodes, the voltammograms for anionic species are greatly attenuated, while for the biogenic amines the peak currents are larger than at uncoated electrodes. Fast-scan voltammetry is shown to be particularly advantageous for the determination of 5-hydroxytryptamine. The short electrolysis time prevents the oxidation products from forming an insulating film on the electrode. Although adsorption of these compounds occurs in their reduced form, this feature is advantageous since it increases the signal-to-noise ratio. Submicromolar detection limits can be achieved because of the preconcentration on the electrode surface.