摘要
用双缩脲法测定牛奶和酸奶中蛋白质含量．采用正交实验优化了测定条件，λmax=536nm，双缩脲加入量4mL，pH=13．55，Cu^2＋浓度=0．008mol／L，室温下放置15min后测定；线形方程相关系数r=0．9991，摩尔吸收系数K=2．61×10^4L／（mol·cm），回收率在97．2％-103．9％，平均变异系数CV=0．83％，线形范围0．016-2mg／mL．该法精密度好，抗干扰能力强，快速、简便，可直接测定牛奶和奶制品中蛋白质．
The concentrations of protein of milk and yoghurt are determined by the methods of Biuret reaction. The reaction conditions were optimized with orthogonal experimental method. The results showed λmax = 536 nm, pH = 13.55, [Cu^2＋] =0. 008 mol/L, 15 min at room temperature; Linear regression equation was calculated with r =0. 999 1 and the apparent molar absorption coefficient 2.61×10^4L/（mol·cm） ,The range of recovery is 97.2%-103.9% and average CV0.83% . The law of dairy protein content is 0. 016 - 2 mg/mL. Sample results indicate that the method with better precision, strong anti-jamming capability is fast and simple. It can be directly applied to the determination of protein in dairy products.
出处
《河南工业大学学报（自然科学版）》
CAS
北大核心
2008年第3期8-11,共4页
Journal of Henan University of Technology：Natural Science Edition
关键词
光度法
双缩脲法
蛋白质
测定
spectrophotometer
biuret
protein
determination
