Safavi Afsaneh, Maleki Norouz, Moradlou Omran, Tajabadi Fariba
Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 71454, Iran.
Anal Biochem. 2006 Dec 15;359(2):224-9. doi: 10.1016/j.ab.2006.09.008. Epub 2006 Oct 4.
A recently constructed carbon composite electrode using room temperature ionic liquid as pasting binder was employed as a novel electrode for sensitive, simultaneous determination of dopamine (DA), ascorbic acid (AA), and uric acid (UA). The apparent reversibility and kinetics of the electrochemical reaction for DA, AA, and UA found were improved significantly compared to those obtained using a conventional carbon paste electrode. The results show that carbon ionic liquid electrode (CILE) reduces the overpotential of DA, AA, and UA oxidation, without showing any fouling effect due to the deposition of their oxidized products. In the case of DA, the oxidation and reduction peak potentials appear at 210 and 135mV (vs Ag/AgCl, KCl, 3.0M), respectively, and the CILE shows a significantly better reversibility for dopamine. The oxidation peak due to the oxidation of AA occurs at about 60mV. For UA, a sharp oxidation peak at 340mV and a small reduction peak at 250mV are obtained at CILE. Differential pulse voltammetry was used for the simultaneous determination of ternary mixtures of DA, AA, and UA. Relative standard deviation for DA, AA, and UA determinations were less than 3.0% and DA, AA, and UA can be determined in the ranges of 2.0x10(-6)-1.5x10(-3), 5.0x10(-5)-7.4x10(-3), and 2.0x10(-6)-2.2x10(-4)M, respectively. The method was applied to the determination of DA, AA, and UA in human blood serum and urine samples.
一种最近构建的以室温离子液体为粘贴粘合剂的碳复合电极被用作一种新型电极，用于灵敏、同时测定多巴胺（DA）、抗坏血酸（AA）和尿酸（UA）。与使用传统碳糊电极获得的结果相比，所发现的DA、AA和UA的电化学反应的表观可逆性和动力学有了显著改善。结果表明，碳离子液体电极（CILE）降低了DA、AA和UA氧化的过电位，且未因它们氧化产物的沉积而显示出任何污垢效应。对于DA，氧化和还原峰电位分别出现在210和135mV（相对于Ag/AgCl，KCl，3.0M），并且CILE对多巴胺显示出明显更好的可逆性。由于AA氧化产生的氧化峰出现在约60mV处。对于UA，在CILE上获得了340mV处的尖锐氧化峰和250mV处的小还原峰。差分脉冲伏安法用于同时测定DA、AA和UA的三元混合物。DA、AA和UA测定的相对标准偏差小于3.0%，并且DA、AA和UA的测定范围分别为2.0×10⁻⁶ - 1.5×10⁻³、5.0×10⁻⁵ - 7.4×10⁻³和2.0×10⁻⁶ - 2.2×10⁻⁴M。该方法应用于人体血清和尿液样品中DA、AA和UA的测定。
