茚三酮比色法测乙肝宁水提物中总游离氨基酸含量

目的:建立乙肝宁复方水提物中总游离氨基酸含量测定的方法。方法:以乙肝宁复方水提物中总游离氨基酸含量和蛋白质含量为指标,对总游离氨基酸含量测定最佳除蛋白的乙醇浓度和药液比进行筛选;采用茚三酮比色分光光度法,于568 nm,测定乙肝宁复方中总游离氨基酸的含量。结果:醇浓度为70%,生药浓度为1 g/mL(生药比1∶6)可较好除去蛋白质等大分子物质,减少测定干扰;采用茚三酮比色法,标准曲线方程为:A=0.055 9C-0.225 3(r=0.999 1),平均回收率为98.8%,RSD为2.07%(n=9),线性关系良好。该法测得乙肝宁复方药材中总游离氨基酸的含量为1.47%,乙肝宁浸膏中含量为5.65%。结论:该方法简便、快速准确,可用于测定乙肝宁复方中游离氨基酸的含量测定。

Determination of total Free-amino acid in Yiganning aqueous extract by Nihydrin colorimetry

Objective:To establish a method for detemlination of total free-amino acid in Yiganning aqueous extract.Methods:The optimum conditions of alcohol precipitation were determined using the concentration of total free-amino acid and protein in Yiganning aqueous extract as testing indexes.Using Spectrophotome-ter to determine the content of total free-amino acid in Yiganning aqueous extract at 568nm with ninhydrin as developer.Results:The optimum conditions of alcohol precipitation was 70% ethanol,and the concentrati-on of the extracted solution was 0.17g raw material per 1 mL.It can efficiently except the macromolecular su-bstances such as protein.Using nihydrin colorimetry,thestandard curve was A=0.0559C-0.2253,r=0.9991,the average recovery was 98.8%,RSD=2.07%(n=9).It has a good linear correlation.The content of total fr-ee-amino acid is 1.48% in Yiganning raw medicinal herbs,5.65% in extract of Yiganning.Conclusions:The guantitative method is simple,rapid,reliable,which can be used for detemlination of total free-amino acid in Yiganning aqueous extract.