一种测定茶叶中茶多酚的光谱新方法  

Determination of Polyphenols in Tea by a New Method Spectrophotometry

作　　者：张淑芳[1] 

机构地区：[1]曲阜师范大学化学科学学院,山东曲阜273165

出　　处：《光谱学与光谱分析》2008年第7期1630-1632,共3页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(20075016);曲阜师范大学基金项目(XJ0716)资助

摘　　要：茶多酚具有较强的还原性，在酸性溶液中可将Fe^3＋还原为Fe^2＋，Fe^2＋与邻二氮菲反应生成橙红色配合物，而阳离子表面活性剂溴化十六烷基三甲胺可以增加邻二氮菲与Fe^2＋显色反应的灵敏度。络合物的最大吸收波长为510nm，表观摩尔吸光系数为0．88×10^5L·mol^-1·cm^-1，据此提出了测定茶多酚的新方法，研究了Fe^2＋与茶多酚及邻二氮菲的反应条件，茶多酚浓度在4．00-32．00μg·mL范围内服从比尔定律。方法的检测限为2．0μg·mL^-1，该方法应用于茶多酚的测定，结果令人满意。The authors developed a method for the determination of tea polyphenols. Phenanthroline is a sensitive regent for the determination of Fe^2＋ , it can react with Fe^2＋ to form an orange complex in acidic solution. A new spectrophotometric method was proposed for the determination of tea polyphenols in tea samples based on that tea polyphenols could react with Fe^3＋ to produce Fe^2＋ , and the orange complex would be formed by the reaction of Fe^2＋ with Phenanthroline in acidic solution. In the presence of positive iron surfactant CTMAB, the sensitivity of chromogenic reaction was improved. The work focused on the optimizing of experiment conditions such as wavelength of determination, buffer solution, surfactant, and the react time etc. At the maximum absorption wavelength of 510 nm, the apparent molar absorptivity was 0. 88×10^5 L· mol^-1 · cm^-1 , Beer＇s law was obeyed in the range of 4.00 to 32. 00μg · mL^-1 Polyphenols. The detection limit was 2.0 μg ·mL^-1. This method was applied to the determination of polyphenols in tea samples with satisfactory results. The method has three merits, namely high level of accuracy and sensitivity, simplicity, and simple equipment

关 键 词：茶叶 茶多酚 分光光度法 

分 类 号：O657.3[理学—分析化学]