靛酚蓝比色法用于甘草酸单铵二铵盐的鉴别

Indophenol blue colorimetric method for identification of diammonium glycyrrhizinate and ammonium glycyrrhizinate

目的:建立专属性强的方法用于甘草酸单铵二铵盐的鉴别。方法:借鉴环境空气中微量氨的测定方法-靛酚蓝比色法,在亚硝基铁氰化钠及次氯酸钠存在下,铵根在稀硫酸中与水杨酸生成蓝绿色的靛酚染料,在698nm波长处测定吸收值,根据显色深浅,比色定量。结果:通过显色后样品管与已知氨含量对照管吸收值的比对,可鉴别出样品为单铵盐还是二铵盐,甘草酸对样品测定无干扰;对国内1个厂家的甘草酸单铵及二铵原料,2个厂家的甘草酸二铵注射液样品进行了鉴别实验,结果均为单铵。结论:上市甘草酸二铵类产品实际铵含量存在名不符实现象,可用本文方法进行其单铵二铵盐的鉴别。

Objective：To establish a specific method for identification of Diammonium glycyrrhizinate and ammonium glycyrrhizinate.Methods：Refer to the determination of trace ammonia in ambient air-indophenol blue colorimetric method,ammonia radical in dilute sulfuric acid could generate blue-green indophenol dye with salicylic acid in presence of sodium nitroprusside and sodium hypochlorite solution,and according to the absorbance at 698 nm,the ammonia radical could be quantitatively determinated.Results：Comparing the absorbance of colorized sample with the absorbance of the control solution which had definite ammonia content,whether the sample was diammonium glycyrrhizinate or ammonium glycyrrhizinate could be identificated,and glycyrrhizic acid didn＇t interfere the identification.Identification has been done to ammonium and diammonium glycyrrhizinate raw material from one domestic pharmaceutical factory,and diammonium glycyrrhizinate injections from two domestic pharmaceutical factories,and the results showed those diammonium glycyrrhizinate was really ammonium glycyrrhizinate.Conclusion：The content of ammonium radical in some approved diammonium glycyrrhizinate products doesn＇t accord with the lable,and the above method is suitable for the identification of diammonium glycyrrhizinate and ammonium glycyrrhizinate.