液相色谱-电喷雾离子阱串联质谱同时分析烟草中的20种游离氨基酸

建立了液相色谱-电喷雾离子阱串联质谱(LC-ESI-IT-MS/MS)同时分析烟草中20种游离氨基酸的方法。烟草样品经萃取后过滤直接进样,无需进行衍生和固相萃取等其他前处理步骤。液相色谱采用HyPURITY C18反相色谱柱(200 mm×2.1 mm, 5 μm),采用1%(体积分数,下同)乙腈水溶液(含0.1%九氟戊酸)和90%乙腈水溶液(含0.1%九氟戊酸)为流动相进行梯度洗脱。结果表明,20种氨基酸的检出限(LOD)为0.01～0.05 μmol/L (S/N=3),线性相关系数均大于0.9977,峰面积测定的相对标准偏差(RSD)为0.78%～4.93%。该方法分析效率、灵敏度和选择性高,已成功应用于多种烟草样品中氨基酸的分析测定。

Simultaneous analysis of twenty free amino acids in tobacco using liquid chromatography-electrospray ionization/ion trap tandem mass spectrometry

A method for simultaneous analysis of 20 free amino acids in tobacco was developed using liquid chromatography-electrospray ionization/ion trap tandem mass spectrometry (LC-ESI-IT-MS/MS). Tobacco samples were extracted and filtered, and analyzed without derivatization or solid phase extraction. The LC separation was carried on a reversed-phase HyPURITY C18 column (200 mm×2.1 mm, 5 μm) with the mobile phase of 1%(v/v) acetonitrile/water solution containing 0.1% nonafluoropentanoic acid and 90% acetonitrile/water solution containing 0.1% nonafluoropentanoic acid in gradient mode. The results showed that the limits of detection (LODs) of 20 amino acids were in the range of 0.01-0.05 μmol/L (S/N=3), the linear correlation coefficients were above 0.9977 in all cases, and the relative standard deviations (RSDs) of peak areas of the extracted ion chromatograms were in the range of 0.78%-4.93%. The developed method is of good efficiency, sensitivity and selectivity, and has been successfully applied to determine the free amino acids in varieties of tobacco samples.