Flow electrochemical determination of ascorbic acid in real samples using a glassy carbon electrode modified with a cellulose acetate film bearing 2,6-dichlorophenolindophenol
Flow electrochemical determination of ascorbic acid in real samples using a glassy carbon electrode modified with a cellulose acetate film bearing 2,6-dichlorophenolindophenol
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DOI：
10.1016/s0003-2670(00)00709-1
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发表时间：
2000-03-23
影响因子：
6.2
通讯作者：
Tzouwara-Karayanni, SM
中科院分区：
文献类型：
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作者：
Florou, AB;Prodromidis, MI;Tzouwara-Karayanni, SM
以2，6-二氯酚靛酚（2，6-dichlorophenolindophenol，CA/DCPI-CME）聚合物膜修饰玻碳电极，构建了抗坏血酸（Vc）传感器。整个反应遵循催化再生机理（EC机理），并对电催化氧化抗坏血酸的电化学速率常数kf进行了评价。将修饰电极安装在流动注射（FI）歧管中，相对于Ag/AgCl/3 M KCl在pH 6.5下保持在+100 mV，并用于测定饮料和药物中的抗坏血酸。与参考方法的相关性良好。测试了各种分子大小的干扰物。校准曲线在0.02-1和0.1-6 mM抗坏血酸的范围内线性CA/DCPI传感器水解KOH和ZnCl 2溶液，分别。通量为每小时25个样品，并且对于在KOH和ZnCl 2溶液中水解的CA/DCPI传感器，0.4mM抗坏血酸溶液的CV分别为0.75（n=14）和1.2%（n=10）。回收率为92- 110%。传感器显示出非常好的可重复性和操作稳定性。(C)2000 Elsevier Science B. V.保留所有权利。
An ascorbate sensor based on a glassy carbon electrode modified with a cellulose acetate polymeric film bearing 2,6-dichlorophenolindophenol (CA/DCPI-CME) was constructed. The overall reaction obeys a catalytic regeneration mechanism (EC mechanism) and the electrochemical rate constant kf for the electrocatalytic oxidation of ascorbic acid was evaluated. The modified electrodes were mounted in a flow injection (FI) manifold, poised at +100 mV versus Ag/AgCl/3 M KCl at pH 6.5 and utilized for the determination of ascorbic acid in beverages and pharmaceuticals. Good correlation with a reference method was attained. Interferents of various molecular sizes were tested. Calibration graphs were linear over the range 0.02-1 and 0.1-6 mM ascorbic acid for CA/DCPI sensors hydrolyzed in KOH and ZnCl2 solution, respectively. The throughput was 25 samples per hour and the CV was for a 0.4 mM ascorbic acid solution 0.75 (n=14) and 1.2% (n=10) for CA/DCPI sensors hydrolyzed in KOH and ZnCl2 solution, respectively. The recovery was 92-110%. The sensors showed very good repeatability and operational stability. (C) 2000 Elsevier Science B.V. All rights reserved.