王贤智 郝淑美 王志洪等

摘要[目的] 分析比较几种不同的前處理方法对咖啡因含量检测的影响，筛选较优的咖啡因提取方法。[方法]以国标水提取方法为对照，研究乙醇提取、氯仿提取、超声提取和微波提取对咖啡因含量检测的影响，并对较优的提取方法进一步优化。[结果] 与国标水提取方法相比，超声提取方法准确度更高，相对误差更小。进一步对超声提取的前处理时间进行优化发现：超声处理45 min以上的咖啡因提取效率与国标方法相比，没有显著差异。[结论]综合考虑咖啡因提取效率及处理时间，确定超声提取45 min为该试验最优的咖啡因提取前处理方法，该方法操作更简单、耗时更少、精密度更高。

关键词咖啡；咖啡因；超声辅助提取；高效液相色谱

中图分类号S571.2文献标识码A文章编号0517-6611（2016）04-110-03

Influence of Different Pretreatment Methods on the Determination of Caffeine Content in Coffee by HPLC

WANG Xianzhi1，HAO Shumei1，WANG Zhihong2，HE Feifei1* （1. School of Agriculture，Yunnan University，Kunming，Yunnan 650091； 2. Yunnan Sanbiao Nonglin Sci. & Tech. Co.，Ltd，Kunming，Yunnan 650032）

Abstract[Objective] To study the influence of five pretreatment methods on the determination of caffeine content by HPLC， and to screen a superior method for caffeine extraction in coffee. [Method] With national standard of water pretreatment as the control， we studied the influence of ethanol extraction， chloroform extraction， ultrasonic extraction and microwave extraction on the determination of caffeine content in coffee， and further optimized the processing time for the superior pretreatment method.[Result] Compared with national standard of water extraction method，ultrasonic extraction had higher accuracy and less relatively error. Optimization of pretreatment time of ultrasonic extraction showed that the extraction rate of caffeine by ultrasonic extraction had no significant differences with that by national standard method，when the extraction time was greater than 45 min. [Conclusion] Considering the extraction rate of caffeine and treatment time，45 min ultrasonic extraction is the optimal pretreatment method for caffeine extraction. This method is simple，accurate and needs less operation time.

Key wordsCoffee； Caffeine； Ultrasonicassisted extraction； HPLC

咖啡因（caffeine，CAF）又名咖啡碱，是一种生物碱类化合物。研究表明，咖啡因具有刺激中枢神经的作用，对神经系统、心脑血管系统、消化系统、肿瘤化疗的生化调节、神经官能症和偏头痛等均有积极作用[1-2]。然而，长期摄入过量咖啡因可能会引起流产、诱发骨质疏松以及高血压、心率失常等心血管系统疾病[3-5]。

咖啡因是衡量咖啡质量的一项重要指标，因此准确测量咖啡中咖啡因的含量十分重要。目前，测定咖啡因的方法有高效液相色谱法（HPLC）、气相色谱法、紫外分光光度法、薄层色谱法、碘量法和重量法等[6-9]，其中常用的方法为高效液相色谱法。传统的HPLC测定前处理方法操作繁琐或涉及氯仿等有害物质，且咖啡因提取率不高，导致重复性差、准确度低。……