电导检测离子排斥色谱法测定绿茶中的没食子酸

建立离子排斥色谱法测定绿茶中没食子酸的分析方法。采用Metrosep Organic Acids(250mm×7.8mm)分离柱和电导检测器，对分离条件进行优化。结果表明：最佳的色谱条件为以0.006mmol/L H2SO4溶液为淋洗液、50.0mmol/L LiCl溶液为再生液、流速0.5mL/min；在优化的分离条件下，绿茶中常见的F－和8种酸对没食子酸的测定均无干扰，总分析时间为19min，没食子酸的检出限为0.1μg/mL；连续6次进样，峰面积相对标准偏差为1.34%，4种绿茶中没食子酸的回收率为87.1%～96.7%。该方法简单、快速，结果令人满意。

Determination of Gallic Acid in Green Tea by Ion Exclusion Chromatography with Conductivity Detection

An ion exclusion chromatographic method for the determination of gallic acid in green tea was described. The optimal chromatographic separation was investigated on Metrosep Organic Acids (250 mm×7.8 mm) column with conductivity detection. The optimal separation was achieved using 0.006 mmol/L sulfuric acid as the eluent, 50.0 mmol/L lithium chloride as the regenerated liquid at a flow rate of 0.5 mL/min. Fluoride and 8 common acids in green tea had no interference on the determination. The total analysis time was 19 minutes. The detection limit of gallic acid was 0.1 μg/mL. The RSD of peak area for six replicate determinations was 1.34%. The recovery percentages in 4 green teas were 87.1%－96.7 %. So, the method has the advantages of simplicity, rapidity and satisfying results.