液相色谱-串联质谱法测定银杏叶提取物及含银杏叶提取物的保健食品中咖啡因的含量

目的建立一种液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry, LC-MS)测定银杏叶提取物及含银杏叶提取物的保健食品中咖啡因的含量的方法。方法样品经甲醇超声提取, C_(18)色谱柱分离,以0.1%甲酸水溶液-0.1%甲酸乙腈溶液(50:50, V:V)为流动相进行等度洗脱,在正离子模式下检测,外标法定量。结果该方法在21.5～1075 ng/mL浓度范围内呈现良好的线性关系,相关系数r为0.9999,平均回收率为97.20%～99.63%,相对标准偏差(relative standard deviation, RSD)小于2.67%。在所检测的6批银杏叶提取物及1批保健食品中均检测出咖啡因,含量范围为0.41～8.71mg/kg。结论该方法专属性强、准确性好、灵敏度高、重现性好,适用于银杏叶提取物及含银杏叶提取物的保健食品中咖啡因的鉴别和含量测定。

Determination of caffeine in Ginkgo biloba extract and health food containing Ginkgo biloba extract by liquid chromatography-tandem mass spectrometry

Objective To establish a method for the determination of caffeine in Ginkgo biloba extract and health food containing Ginkgo biloba extract by liquid chromatography-tandem mass spectrometry (LC-MS). Methods The sample was ultrasonically extracted by methanol, separated by C18 column. The sample elution was conducted by gradient elution with 0.1% formic acid aqueous solution-0.1% formic acid acetonitrile solution (50:50, V:V) as mobile phase. The sample was detected in positive ion mode and quantified by external standard method. Results This method showed a good linear relationship in the concentration range of 21.5-1075 ng/mL. The correlation coefficient (r) was 0.9999, the average recovery was 97.20%-99.63%, and the relative standard deviation (RSD) less than 2.67%. Caffeine was detected in the 6 batches of Ginkgo biloba extract and 1 batch of health foods, and the content ranged from 0.41-8.71 mg/kg. Conclusion This method has strong specificity, good accuracy, high sensitivity and good reproducibility, which is suitable for the identification and determination of caffeine in Ginkgo biloba extract and health food containing Ginkgo biloba extract.