本文报导了在乳土糖生产过程中用甲胺·紫外光谱法测定糖浆内乳糖的含量;间接测定乳土糖的含量。乳糖含量于1-4.5mg/20m1范围内,在波长278.4nm处测定其吸光度与浓度呈良好的线性关系,符合朗伯·比尔定律。乳土糖同时存在不干扰。实验结果,回收率为95.4％～102.2,变异系数小于0.891％(n=9)。 In this paper, the content of lactose in syrup was determined by methylamine UV spectrophotometry during lactose production. The content of lactose was measured indirectly. Lactose content in 1-4.5mg / 20m1 range, measured at a wavelength of 278.4nm at a good linear relationship between absorbance and concentration, in line with Lambert Beer’s Law. Milk sugar does not interfere with the same time. The experimental results showed that the recoveries ranged from 95.4% to 102.2 and the coefficients of variation were less than 0.891% (n = 9).