茚三酮柱后衍生法测定丙氨酰-谷氨酰胺的含量

目的建立茚三酮柱后衍生化氨基酸分析仪测定N（2）-L－丙氨酰－L－谷氨酰胺（L－Ala－L－Glu）含量的方法。方法根据L－Ala－L－Glu与茚三酮反应后溶液在570nm处有最大吸收的原理，以钾钠缓冲液为流动相，将L－Ala-L－Glu洗脱后，与茚三酮进行柱后衍生反应，生成可以被分光光度计检测的有色物质，氨基酸分析仪测定L—Ala-L－Glu的含量。结果L－Ala-L-Glu在1-20mg·L^-1、内线性关系良好（r=0.9979），低、中、高3种浓度的回收率分别为94．5％，97．6％和98.7％；RSD分别为0.52％，0．10％和O．06％。结论本法操作简单，分离度良好，结果准确可靠，可用于L－Ala－L－Glu的含量测定。

Determination of N(2)-L-alanyl-L-glutamine by Post-Column Derivatization with Ninhydrin

OBJECTIVE To establish a method using post-column derivatization with ninhydrin for determination of N(2)-L-alanyl-L-glutamine(L-Ala-L-Glu). METHODS According to principle of solution having maximum absorption in 570 nm, potassium sodium buffer as mobile phase, L-Ala-L-Glu was eluted and reacted with ninhydrin, the production can be detected by spectrophotometer, amino acid analyzer determined the content of L-Ala-L-Glu. RESULTS The linear relation was good in the range of 1-20 mg·L^-1 (r=0.997 9). The recoveries of low, middle and high concentration were 94.5%, 97.6% and 98.7% with the RSD of 0.52%, 0.10% and 0.06%, respectively. CONCLUSION This method is simple, separating degree is good, results are accurate and reliable, and can be used in the determination of L-Ala-L-Glu.