RESUMEN
A RP-HPLC method for the quantification of the six major bovine milk proteins (κ-casein (CN),α_(s2)-CN,α_(s1)-CN,β-CN,Whey,immunoglobulins (Igg) ) is described. Separation and quantification were achieved by a reversed phase analytical column (Agilent Zorbax 300SB-C_8,250 mm×4.6 mm ,5μm) and the gradient elution solvents of 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in acetonitrile at a flow rate of 0. 8 mL/min. Column temperature was set at 45℃ and the sample was monitored with photodiode array detector at 214 nm. A linear relationship( r >0. 999) between the concentrations of proteins and peak areas was observed over the concentration range. Recoveries of six target proteins spiked in milk were form 74. 8% to 132.5%. Nine kinds of milks of different brands were analyzed,and the difference of the concentration and relative ration of κ-CN,α_(s2)-CN,α_(s1)-CN,β-CN and Whey were found.