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目的建立适合于不同饮品中的咖啡因含量检测的高效液相色谱方法。方法可乐型饮料、含乳及不含乳的咖啡及茶叶液体制品、咖啡、茶叶及其固体制品等样品用水提取后,不同类型的饮品经过不同的前处理净化方法,经Symmetry Shield C18反相色谱柱(3.9 mm×150 mm×5μm)分离,用二极管阵列检测器检测,保留时间定性,外标法定量分析。结果咖啡因在220 ng/ml~439μg/ml浓度范围内与峰面积呈良好的线性相关,相关系数r=0.9998,以3倍基线噪音信号确定检出量为0.7 ng;不同饮品3水平添加量的平均回收率为90.2%~107%,测定结果的相对标准偏差(RSD)为0.37%~3.8%(n=6)。结论本方法检测灵敏度高,重现性和准确性好,具备科学性以及可操作性,可用于不同饮品中咖啡因含量的测定。
Objective To establish a HPLC method suitable for the determination of caffeine in different drinks. Methods Coke-type beverages, milk and non-dairy coffee and tea liquid products, coffee, tea and solid products and other samples were extracted with water and the different types of drinks were subjected to different pretreatment purification methods and Symmetry Shield C18 reverse phase chromatography Column (3.9 mm × 150 mm × 5 μm) separation, detection with a diode array detector, retention time qualitative, external standard quantitative analysis. Results Caffeine showed a good linear correlation with the peak area in the concentration range of 220 ng / ml ~ 439 μg / ml with a correlation coefficient of 0.9998. The detection yield of caffeine was 0.7 ng with 3 times the baseline noise signal. The average recovery was 90.2% ~ 107%. The relative standard deviations (RSDs) were 0.37% ~ 3.8% (n = 6). Conclusion The method has high detection sensitivity, reproducibility and accuracy, is scientific and practical, and can be used for the determination of caffeine in different drinks.