茚三酮柱后衍生法测定丙氨酰-谷氨酰胺的含量

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

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570 nm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1～20 mg.L-1内线性关系良好(r=0.997 9),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0.06%。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。

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.