茶叶中多种氨基酸15N同位素丰度的检测研究

建立了气相色谱-质谱联用（GC-MS）测定茶叶中丙氨酸、丝氨酸、谷氨酸、天冬酰胺、茶氨酸、谷氨酰胺氨基酸同位素丰度的检测方法。茶叶样品经浸泡提取后，经N-甲基-N-（三甲基硅烷）三氟乙酰胺（MSTFA）进行衍生，在优化的色谱-质谱条件下，6种目标氨基酸衍生物均检出。验证了丙氨酸、丝氨酸、谷氨酸、天冬酰胺、茶氨酸、谷氨酰胺的¹⁵N同位素丰度在10%~98%内均可以被准确测定。建立的方法精密度优于0.6%，绝对偏差小于0.6%。所建立的方法样品前处理简单，同位素丰度检测准确，可满足茶叶中标记氨基酸同位素丰度检测，该方法也可推广至不同农作物中氨基酸同位素丰度的检测，为植物中氨基酸相关转化路径及代谢循环研究提供技术支持。

Determination of Isotopic Abundance of 15N-Labeled Amino Acids in Tea

A method for determination alanine, serine, glutamic acid, asparagine, theanine, glutamine in tea leaves by MSTFA derivatization has been established. And six amino acids were detected successfully. Isotope abundance of alanine, serine, glutamate, asparagine, theamine and glutamine are calculated accuracy, isotope abundance range from 10% to 98% (atom%). The relative standard deviations (RSD, n=3) were below 0.6%, and absolute deviation were below 0.6%. The method is quick, easy and accurate, which can meet the detection on isotope abundance of labeling amino acids in tea leaves. Besides, the method also can be applied to the determination of isotopic abundance of amino acids in other different crops, and provides technical support for the research of amino acids related transformation pathways and metabolic cycles in plants.