Mizukami Yuzo, Sawai Yusuke, Yamaguchi Yuichi
National Institute of Vegetable and Tea Science, 2769 Kanaya, Shimada, Shizuoka 428-8501, Japan.
J Agric Food Chem. 2007 Jun 27;55(13):4957-64. doi: 10.1021/jf070323f. Epub 2007 May 26.
We developed a high-performance liquid chromatography-based method for simultaneous analysis of nine catechins, gallic acid, strictinin, caffeine, and theobromine in green tea by using catechol as an internal standard. Although the high cost and instability of the catechin reference standards limit the application of this method, the addition of ascorbic acid to the standard stock solution preserved the stability of the reference standards in the solution for 1 year when stored at -30 degrees C. Furthermore, we found that the slopes of the calibration curves plotted were stable for a run time of 2000 h. Our method proved to be appropriate for quantification and yielded good correlation coefficients, detection levels, repeatability, reproducibility, and recovery rates. Quantitative data revealed that the contribution of only 200 mL of brewed tea to the total dietary catechins was approximately 220-420 mg, while that of 500 mL of bottled tea was approximately 170-900 mg.
我们开发了一种基于高效液相色谱的方法，以儿茶酚为内标，同时分析绿茶中的九种儿茶素、没食子酸、三叶苷、咖啡因和可可碱。尽管儿茶素参考标准品的高成本和不稳定性限制了该方法的应用，但在标准储备溶液中添加抗坏血酸后，当在-30℃下储存时，参考标准品在溶液中的稳定性可保持1年。此外，我们发现绘制的校准曲线斜率在2000小时的运行时间内保持稳定。我们的方法被证明适用于定量分析，具有良好的相关系数、检测限、重复性、重现性和回收率。定量数据显示，仅200 mL冲泡茶对总膳食儿茶素的贡献约为220 - 420 mg，而500 mL瓶装茶的贡献约为170 - 900 mg。
