自动电位滴定法测定对氨基苯酚氨基值

Determination of Amino-value of p-Aminophenol by Automatic Potentiometric Titration

建立了一种利用自动电位滴定仪测定对氨基苯酚(PAP)氨基值的方法,根据重氮化反应的原理,分别从反应温度、滴定方式以及无机酸的种类和浓度条件进行了优化,样品在氢溴酸/盐酸体系,35℃滴定温度自动滴定氨基值。结果表明,对氨基苯酚样品的氨基值与手动滴定法相差较小,加标回收率在98.8%~101%,与国家标准方法“GB/T 21892—2015”对比,具有操作简便,自动化程度高,滴定终点判断敏锐,测定结果准确可靠的优点,可用于PAP的氨基值测定。

An automatic potentiometric titration method for determination of amino-value of p-aminophenol(PAP)was established.According to the principle of diazotization reaction,the reaction temperature,titration method and the type and concentration of inorganic acid were optimized.The amino-value of the sample was titrated automatically in 30%hydrobromic acid/hydrochloric acid system at 35℃.The difference of automatic titration and manual titration is small,and the recovery is between 98.8%and 101%.Compared with GB/T 21892—2015,this method has the advantages of simple operation,high degree of automation,sharp judgment of titration point,accurate and reliable determination results,and can be used for determination of amino-value of PAP.