法根据弱酸在水溶液中各种形式的分布系数只与溶液ｐＨ有关的原理，先将含蛋白质样品消化成硫酸铵弱酸形式，再用一定浓度的氢氧化钠溶液滴定到某一固定ｐＨ值。利用试液中所含（ＮＨ＿４）＿２ＳＯ＿４量与滴定时消耗碱溶液体积成正比关系测定蛋白质总量。操作简单、快速、滴定剂不需标定浓度，也不需确定化学计量点。用本法和传统的凯氏定氮法对照测定大豆和花生样品中蛋白质总量，其结果相当吻合。 According to the principle that the distribution coefficient of various forms of weak acid in aqueous solution is only related to the pH value of the solution, the protein-containing sample is first digested into the weak acid form of ammonium sulfate and titrated to a fixed pH value with a certain concentration of sodium hydroxide solution. The amount of (NH_4) _2SO_4 contained in the test solution is used to determine the total amount of protein in proportion to the volume of alkali solution consumed during titration. Simple, fast, titrant does not require calibration concentration, also do not need to determine the stoichiometry point. This method and the traditional Kjeldahl method for the determination of soybean and peanut protein samples in the sample, the results quite consistent.