中文摘要：

建立了以微波-超声协同萃取茶叶中咖啡因的样品前处理方法,优化了影响萃取效率的各种因素,包括萃取剂体积、萃取功率、萃取时间、萃取温度等,获得了优化的实验条件,即：三氯甲烷15mL,微波功率400 W,萃取时间10min,萃取温度65℃.在优化的实验条件下,结合紫外可见分光光度法测定了不同茶叶中咖啡因的质量分数,获得满意结果.

英文摘要：

A microwave-ultrasonic synergistic sample pretreatment technique has been proposed for the fast extraction of caffeine in tea leaf.Various factors affecting the extraction of caffeine,including volume of extractant,microwave power,extraction time and extraction temperature,have been optimized.The optimized conditions were as follows：15mL of chloroform,400 Wof microwave power,10 min of extraction time and 65 ℃ of extraction temperature.Under the optimal conditions,a microwave-ultrasonic synergy extraction combination of UV spectroscopy has been applied to determine the content of caffeine in various tea leaf samples successfully.