气-质联用法测定莲子心中的氨基酸

Determination of amino acids in seed embryo of Nelumbo nucifera Gaertn by gas chromatography-mass spectrometry

目的:建立用气相色谱-质谱联用技术对中药莲子心中的氨基酸进行定性定量分析的方法。方法:莲子心采用水(1∶35)、6 mol·L-1盐酸(1∶25)高温回流提取,提取液经BSTFA+1%TMCS衍生后进样,采用全扫描(Scan)定性,选择离子监测(SIM)内标法定量。色谱柱为HP-5MS石英毛细管柱(30 m×0.25μm×0.25 mm),初始柱温为100℃,保持3 min,程序升温8℃·min-1至300℃,保持6 min,分流比为10∶1。结果:测得水解氨基酸15种,游离氨基酸13种,总含量分别为7.14%和0.13%。样品的平均回收率(n=5)在85.7%～109.2%之间;RSD在0.77%～4.85%之间。结论:该方法处理过程简单,灵敏度和选择性高,可用于莲子心中氨基酸的分析测定。

OBJECTIVE To develop a method to determine free amino acid and hydrolytic amino acid in seed embryo of Ne lumbo nucifera Gaertn by Gas Chromatography-mass speetrometry（GC - MS）. METHODS Amino acids with derivatization of silanization were separated and identified on HP-5MS column （30m×0.25μm×0.25mm）. The initial column temperature of 100℃ was held for 3 min, then programmed at 8 ℃-min 1 to 300 ℃ and maintained at this temperature for further 6 rain. Identification was performed on the basis of the retention time and the mass peak intensity ratio. Quantitative determination was performed using the internal standard technique and the internal standard was sarcosine. RESULTS The separation was repeatable with relative standard deviation （RSD） （n = 5） within 0. 01% - 0. 07% and 0. 83G - 4. 41 % in terms of retention time and peak area, respectively. The spiked recoveries of the samples were in the range of 85.7% - 109. 2% and the relative standard deviations were 0. 77% -4. 85%. 15 kinds of hydrilyzed amino acids and 13 kinds of free amino acids were found in seed embryo of Nelurnbo nucifera Gaertn. The total contents were 7. 14% and 0. 13%, respectively. CONCLUSION The method which can analyze amino acids in seed embryo of Nelumho nucifera Gaerm is simple, accurate, sensitive and suitable for determining amino acids in other plants.