提出一种测定牛奶中尿素的新方法 ,以刀豆粉提取液作脲酶催化尿素水解产生氨 ,氨由水扬酸盐光度法测定 .本法中有色化合物的最大吸收波长 70 0nm ,表观摩尔吸光系数ε 70 0 =1.3×10 4 mol-1.L .cm - 1,线性范围 0～ 0 .8μgN/mL ,,检出限 1.1× 10 -6gN/L A new method for the determination of urea in milk is proposed, in which a soybean extract is used as a urease to catalyze the urea hydrolysis to generate ammonia, which is determined by the salicylate spectrophotometric method. The maximum absorption wavelength of the colored compounds in this method is 70 0 nm, The absorbency ε 70 0 = 1.3 × 10 4 mol-1.L · cm -1, the linear range of 0 ~ 0.8μgN / mL, the detection limit of 1.1 × 10 -6gN / L