测定饮料中咖啡因含量的综合性实验  

Comprehensive Experiment for Determination of Caffeine Content in Beverages

作　　者：张文珠[1] 王添爽 赵洋[1] 冯晴晴 潘玉珍[1] 刘潇彧[1] 

机构地区：[1]大连理工大学化工与环境生命学部基础化学实验中心,辽宁大连116024

出　　处：《实验室研究与探索》2016年第1期13-15,共3页Research and Exploration In Laboratory

基　　金：国家自然科学基金项目(No.21205009);大连理工大学教学改革基金项目(HG201427)

摘　　要：结合有机化学实验内容,采用蒸馏法用乙醇溶剂从茶叶中提取咖啡因晶体,用高效液相色谱仪考察了流动相组成对样品分离效果的影响,发现增大甲醇浓度,咖啡因的保留时间随之减少。咖啡因浓度20-100μg/m L,线性方程为A=2.38C＋33.4,R2=0.991。最后,通过高效液相色谱法（HPLC）测定市售绿茶饮料、可乐和功能饮料中的咖啡因含量,所得色谱图中无干扰叠加峰,并且在几种饮料中均含有一定量的咖啡因,建议需适量摄取含咖啡因的饮料。This experiment for determination of caffeine content was designed in the paper. Firstly,using solvent extract method,caffeine crystal was extracted from tea by ethanol as a solvent. Then the effect of mobile phase in sample separation has been investigated by HPLC. As increasing the concentration of methanol,the retention time of caffeine decreased accordingly. Next,the external standard method was established to detect the caffeine concentrations in highperformance liquid chromatography. The linear equation A = 2. 38 C ＋ 33. 4 held a good linear fitting in the range of 20—100 μg / m L. and the square of the correlation coefficient was 0. 991. Finally,caffeine concentrations in several beverages such as green tea,coke and energy drinks bought from supermarket were detected by HPLC,No interference peaks were observed in the chromatograms. Caffeine was found in all of these beverages,so the public should reduce intake of caffeine containing drinks.

关 键 词：咖啡因 高效液相色谱法 提取 

分 类 号：O657.72[理学—分析化学]