自动蒸馏滴定系统测定食品中蛋白质含量的分析

目的 建立自动蒸馏滴定系统测定食品中蛋白质含量的分析方法。方法样品经过消化处理后，采用VELPUDK152自动蒸馏滴定系统进行蒸馏滴定，根据酸的消耗量求出蛋白质的含量。结果在含氮量0-30mg浓度范围内，方法线性良好（r〉0．999），检出限为0．108mg（含氮量），分别对低中高三个浓度各进行12次测定的变异系数分别为3．32％、3．12％和1．87％，回收率为95．12％～106．94％。结论用自动蒸馏滴定系统测定蛋白质含量的操作简便，检出限低，结果准确，灵敏度高。

Determination of protein content in food by automatic distilling and titrating system

Objective To establish an analytical method for the determination of protein in food by automatic distilling and titrating system. Methods The samples were distilled and titrated by VELP UDK152 automatic system after digested. The content of protein was calculated according to the consumption of acid. Results There was a good linear correlation （r〉0.999） within the content of 0-30mg. The limit of decteion was 0.108mg.The coefficient of variation were 3.32%,3.12% and 1.87% at low ,medium,and high contents. The recovery was between 95.12%-106.94%. Conclusion The method is simple, accurate and highly sensitive.