College of Chemistry and Material Science, Shandong Agricultural University, Taian, 271018 Shandong, China.
Food Chem. 2012 Sep 15;134(2):1225-30. doi: 10.1016/j.foodchem.2012.02.197. Epub 2012 Mar 7.
A simply electrochemical method based on CdSe microparticles modified glassy carbon electrode (GCE) was developed to determine theophylline using cyclic voltammetry and differential pulse voltammetry. Theophylline showed a well-defined oxidation peak at the fabricated electrode in phosphate buffer solution and the oxidation peak current is much higher than that at the bare GCE, indicating that CdSe can effectively improve the oxidation of theophylline. Several effect factors on theophylline determination were optimised, such as CdSe amount, solution pH, scan rate and accumulation time. Under the optimal conditions, the oxidation peak current of theophylline was proportional to its concentration in the range of 1.0-40 and 40-700 μM with a correlation coefficient of 0.9974 and 0.9956, respectively. The limit of detection was estimated to be 0.4 μM (S/N=3). The developed method showed good reproducibility and excellent selectivity. The fabricated electrode was successfully used to determine theophylline in tea, carbonated cola drink, fruit juice drink, fermented milk drink and preserved fruit with acceptable recovery.
一种基于 CdSe 微粒修饰玻碳电极（GCE）的简单电化学方法已被开发出来，用于使用循环伏安法和差分脉冲伏安法测定茶碱。茶碱在磷酸盐缓冲溶液中的制备电极上呈现出明显的氧化峰，并且氧化峰电流比在裸 GCE 上高得多，表明 CdSe 可以有效地提高茶碱的氧化。优化了茶碱测定的几个影响因素，如 CdSe 量、溶液 pH 值、扫描速率和积累时间。在最佳条件下，茶碱的氧化峰电流与其浓度在 1.0-40 和 40-700 μM 范围内呈正比，相关系数分别为 0.9974 和 0.9956。检测限估计为 0.4 μM（S/N=3）。所开发的方法表现出良好的重现性和优异的选择性。该制备电极成功地用于测定茶、碳酸可乐、果汁饮料、发酵乳饮料和水果中的茶碱，回收率可接受。
