直接固体相紫外分光光度法测定茶叶中的茶多酚

Direct solid-phase ultraviolet spectrometric determination of tea polyphenol in tea leaves

探讨溶液的酸碱度、温度、时间等对β-环糊精树脂(β-CDP)包结茶多酚的影响,提出最佳包结条件为温度20℃、时间2.5h、pH4.0。被β-CDP包结的茶多酚其最大吸收峰出现在279nm,在一定的浓度范围内,其含量与吸光度法成正比。所提出的方法用于绿茶和红茶样品中茶多酚含量的测定,结果满意。方法的标准添加回收率92.7%～96.4%,灵敏度是传统的液体相紫外分光光度法的9.1倍。

The effects of the intensities of acid and base, temperature and inclusion time on β-cyclodextrin polymer (β-CDP) including tea polyphenol have been studied. The optimum inclusion conditions were temperature 20℃, inclusion time 2.5h and pH5.0. The maximum absorbance of tea polyphenol in β-CDP appeared at 279nm. Under the range of certain concentration, the absorption intensities of tea polyphenol were linear to the contents of tea polyphenol. The proposed method was applied to determination of tea polyphenol in green tea and black tea samples with satisfactory results. The recovery of the added standard tea polyphenol was the range of 92.7%～96.4%. The sensitivity of the proposed method was 9.1 times of the conventional liquid-phase ultraviolet spectrometry.