Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, Cluj-Napoca, Romania.
J Sep Sci. 2010 Dec;33(23-24):3794-9. doi: 10.1002/jssc.201000554.
The aim of this paper is to develop a new simple, fast and economical method for simultaneous quantitative determination of methylxanthine compounds based on TLC combined with image analysis. To obtain certain results, both extraction and chromatographic separation were optimized. The optimum extraction conditions were maceration in ethanol-water 8:2, v/v. The chromatographic separations were done on the silica gel F(254) TLC plates developed with chloroform-dichloromethane-isopropanol, 4:2:1 v/v/v. Detection was performed under UV lamp at 254 nm and the evaluation of the chromatographic plate was based on digital processing of chromatographic images. The developed TLC method was validated for parameters such as specificity, linearity and range, LOD and LOQ, precision, robustness and accuracy. This method was then applied for determination of caffeine, theobromine and theophylline in different types of tea, commercially available. Moreover, the content of methylxanthines detected and determined in commercial tea samples can be used as chemical marker in quality control.
本研究旨在开发一种新的简单、快速、经济的基于 TLC 结合图像分析的同时定量测定甲基黄嘌呤化合物的方法。为了获得某些结果，对提取和色谱分离进行了优化。最佳提取条件为乙醇-水 8:2（v/v）的浸渍提取。在硅胶 F(254) TLC 板上进行色谱分离，展开剂为氯仿-二氯甲烷-异丙醇，4:2:1（v/v/v）。在 254nm 下进行检测，并基于色谱图像的数字处理来评估色谱板。该 TLC 方法针对特异性、线性和范围、LOD 和 LOQ、精密度、稳健性和准确性等参数进行了验证。然后，该方法应用于不同类型市售茶中咖啡因、可可碱和茶碱的测定。此外，在商业茶样中检测和测定的甲基黄嘌呤含量可用作质量控制的化学标志物。
