超声波提取―高效液相色谱法测定茶叶中的槲皮素

Determination of Quercetin in Tea by Ultrasonic Extraction Coupled with High Performance Liquid Chromatography

采用超声波提取茶叶中的槲皮素,优化了提取溶剂的体积分数、提取时间和固液比,并联用高效液相色谱法测定4种茶叶中槲皮素的质量分数,色谱条件为V（乙腈）∶V（0.2％磷酸溶液）=30∶70,流速1.0 mL/min,检测波长360 nm,柱温30℃.测定结果表明：普洱熟茶中槲皮素质量分数最高,为0.143 8 mg/g,普洱生茶次之,两种绿茶的质量分数最低,方法精密度在2.5％～4.7％之间.

The quercetin if four teas was determined by ultrasonic extraction coupled with high performance liquid chromatography. The extraction conditions were optimized,including extraction solvent, extraction time and solid-liquid ration. Coupled with high performance liquid chromatography the mass fraction of quercetin in four sorts of tea is determined. The mobile phase was acetonitrile and 0. 2% phosphoric acid solution （the volume ration of 30：70） with a flow rate of 1.0 mL/min. The detection wavelength was 360 nm and the column temperature was 30 ~C. The results showed that the content of quercetion in Puer ripe tea was the highest. It was 0. 143 8 mg/L. The content of quercetion in two green teas was the lowest. The content of quercetion in Puer raw tea was in the middle. The detection precision was in the range of 2. 5% to 4.7%.