Catechin can effectively prevent the occurrence of cancers due to its strong antioxidant capacity. In this study, the catechin contents of black teas from 12 different regions of south China were investigated using fluorescence spectroscopy. Herein, the catechin contents of various black teas with constant concentration were determined at the optimal excitation and emission wavelength combining the standard addition method and fluorescence spectroscopy. The results indicated that there was a linear relationship between the obtained concentration and fluorescence intensity, where the R values were all greater than 0.99 and the limit of quantification (LOQ) was 0.02 μg/mL. Furthermore, the content of catechin monomer in the chlorophyll environment was measured under the same experimental conditions to demonstrate the correctness of the above experimental methods. It revealed that the experimental error was about 1.14% compared with the actual content. The current work was proved to be an efficient way to detect fluorescence spectrum through diluting the concentration of tea samples, thereby increasing the determination limit of catechin.

中文翻译：

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荧光光谱法快速测定红茶中儿茶素的含量

儿茶素由于其强大的抗氧化能力，可以有效地预防癌症的发生。在这项研究中，使用荧光光谱法研究了华南12个不同地区的红茶中儿茶素含量。在此，结合标准添加方法和荧光光谱法，在最佳激发和发射波长下测定了各种浓度恒定的红茶中儿茶素的含量。结果表明，所获得的浓度与荧光强度之间存在线性关系，R值均大于0.99，定量限（LOQ）为 0.02μL。克/毫升。此外，在相同的实验条件下测量叶绿素环境中儿茶素单体的含量，以证明上述实验方法的正确性。结果表明，实验误差与实际值相比约为1.14％。事实证明，通过稀释茶叶样品的浓度，从而增加儿茶素的测定限，目前的工作是检测荧光光谱的有效方法。