茯砖茶中黄酮的提取及含量测定

Extraction and Determination of Flavonoids from Fuzhuan Tea

研究了茯砖茶中黄酮的最佳提取及测定条件,以95%乙醇为溶剂,加热回流提取茯砖茶中的黄酮,采用分光光度法检测黄酮含量。在料液比为1∶20g/mL,加热回流60min时,黄酮的提取率最高;当波长为416nm,0.1mol/LAlCl3-甲醇显色液与HAc-NaAc缓冲液(pH=4.0)的体积比为1∶1,显色时间为15min时,吸光度最大。对照样品的线性回归方程为A=0.0203+0.0176C(μg/mL),相关系数r=0.9997,线性范围10—50μg/mL,检出限2.5μg/mL;测得茯砖茶样品中黄酮的含量为1.80%,RSD为1.27%(n=5),对照样品的平均加标回收率为99.0%—102.8%。方法操作简便、快速、准确,能满足茯砖茶中总黄酮的提取和检测的要求。

The optimum conditions for extraction and determination of flavonoids in Fuzhuan tea were investigated with 95% ethanol as solvent,and flavonoids in Fuzhuan tea was extracted by heating reflux method.The content of flavonoids was determined by spectrophotometry,and the extraction rate of flavonoids was the highest under the optimal conditions that were as follows：the solid-liquid ratio was 1∶20（g/mL）,heating reflux time was 60min.The absorbance was maximum,when conditions were as follows：wavelength was 416nm,added the volume ratio of HAc-NaAc（pH=4.0）to 0.1mol/L AlCl3-methanol solution was 1∶1,coloration time was 15min.The linear regression equation of control sample was A=0.0203＋0.0176C（μg/mL）（r=0.9997） in the range of 10—50μg/mL with the detection limit of 2.5μg/mL.The obtained flavonoids content of Fuzhuan tea was 1.80%.The average recoveries were form 99.0% to 102.8%,the RSD（n=5） was 1.27%.The method is simple,rapid and accurate,and can meet the requests of extraction and detection of flavonoids in Fuzhuan tea.