目的 建立高效液相色谱法测定茶多酚中两种主要儿茶素类成分表没食子儿茶素没食子酸酯（EGCG）、表儿茶素没食子酸酯（ECG）及限量成分咖啡因（CAF）含量的方法。方法 色谱柱为Agilent ZORBAX SB-C₁₈柱（4.6 mm×250 mm，5 μm）；流动相：A为乙腈，B为0.05%磷酸水溶液；梯度洗脱条件：0~18 min，12%A；18~20 min，12%A→16%A；20~35 min，16%A；流速：1 mL·min-1；柱温：30 ℃；检测波长：278 nm。结果 茶多酚中EGCG、ECG、CAF的线性范围和相关系数分别为159.4～797.0 mg·L-1 (r=0.999 6)，40.16～120.18 mg·L-1 (r=0.999 7)，1.6～12.8 mg·L-1 (r=0.999 9)；定量限分别为0.8、0.8、1.0 ng；检测限分别为0.25、0.25、0.30 ng；平均加样回收率分别为98.94% （RSD=0.72%），99.45% （RSD=1.00%），100.46%（RSD=0.83%）；方法精密度及重复性良好，RSD均小于2%。结论 本方法操作简便、定量准确、重现性好，适用于茶多酚中EGCG、ECG及CAF含量的测定。

OBJECTIVE To establish a HPLC method for the simultaneous determination of two main catechins (EGCG and ECG) and caffeine (CAF) which is a content limited substance in tea polyphenols. METHODS The separation was performed on a C₁₈ column (Agilent ZORBAX SB-C₁₈，4.6 mm×250 mm，5 μm) with the mobile phase consisting of acetonitrile（A）-0.05% phosphoric acid aqueous solution（B）by gradient elution. The gradient condition was as follows： 0-18 min，A：12%；18-20 min，A：12%-16%；20-35 min，A：16%. The flow rate was 1 mL·min-1. The column temperature was set at 30 ℃，and the UV detection wavelength was 278 nm. RESULTS The linear ranges and correlation coefficients of EGCG、ECG and CAF in tea polyphenols were 159.4-797.0 mg·L-1 (r=0.999 6)，40.16-120.18 mg·L-1 (r=0.999 7) and 1.6-12.8 mg·L-1(r=0.999 9) respectively. The limits of quantitation were 0.8，0.8 and 1.0 ng respectively. The limits of detection were 0.25，0.25 and 0.30 ng respectively. The average recoveries were 98.94%，99.45% and 100.46% with corresponding RSDs of 0.72%，1.00% and 0.83%，respectively. The RSDs were smaller than 2.0%. CONCLUSION The method is simple，accurate，reproducibility and can be used to determine EGCG，ECG and CAF in tea polyphenols.