茯砖茶中咖啡碱与EGCG的HPLC检测分析

Analysis of caffeine and EGCG in the Fu brick tea by HPLC

利用高效液相等度洗脱法研究人工接种条件下茯砖茶中咖啡碱和EGCG的检测条件及含量.结果表明,HPLC的检测条件为:流动相A甲醇,B 5×10^(-5)mol/L KH2PO4溶液(p H=5),A∶B=20∶80,咖啡碱和EGCG的进样量在25~400μg范围内与峰面积呈良好的线性关系,r>0.999 0,咖啡碱和EGCG的平均加标回收率及RSD分别为98.32%、97.18%、1.96%、1.73%,该方法分离效果好,重复性高,可用于同时测定茯砖茶中咖啡碱与EGCG的含量.在此基础上,第一、二次汽蒸后接种及CK成品茶的咖啡碱含量分别为23.63 mg/g、20.08 mg/g、24.37mg/g,其EGCG的含量分别为6.43 mg/g、3.79 mg/g、8.31 mg/g,第二次汽蒸后接种最适宜.

Under the conditions of artificial inoculation,this paper researched the test conditions and content of caffeine and EGCG in the Fu brick tea through HPLC isocratic elution.The results showed that HPLC test conditions were as follows：mobile phase A is methanol,mobile phase B is 5×10-5mol/L KH_2PO_4solution（pH = 5）,A ∶ B = 20 ∶ 80,the injection volume of caffeine and EGCG and peak area showed a good linear relationship in the range of 25400 μg,r0.999 0,the average recoveries and RSD of caffeine and EGCG were 98.32%,97.18%,1.96% and 1.73% respectively,this method is of good separation effect and high repeatability,which can be used for simultaneous determination of the content of caffeine and EGCG in the Fu brick tea.On this basis,the content of caffeine in the first and the second steaming after inoculation and CK finished tea were 23.63 mg/g,20.08 mg/g and 24.37mg/g respectively,and their EGCG content were 6.43 mg/g,3.79 mg/g and 8.31 mg/g respectively.After the second steaming inoculation was the most suitable.