本检测方法在已有检测方法资料的基础上,通过改变柱温和梯度洗脱条件,提高A1 β-酪蛋白和A2 β-酪蛋白的分离效果,以便更好的分析乳制品中A1 β-酪蛋白和A2 β-酪蛋白的含量。本检测方法使用盐酸胍、二硫苏糖醇使β-酪蛋白变性,流动相选择B（乙腈）,A（0.1 %三氟乙酸水溶液）,流速0.5 mL/min,梯度洗脱,柱温50 ℃,反相色谱柱进行分离,紫外检测器214 nm检测。采用本方法可以较好地分离牛乳中的A1 β-酪蛋白和A2 β-酪蛋白,并且出峰时间稳定。A1 β-酪蛋白在0.16~1.65 mg/mL浓度范围内线性关系良好,回归方程y=1.25×106x-1.44×105,R2=0.9985,R=0.9992,回收率范围96.4%~105.0%,精密度小于2.0%;A2β-酪蛋白在0.34~3.35 mg/mL浓度范围内线性关系良好,回归方程y=3.16×106x-3.16×105,R2=0.9988,R=0.9994,三浓度水平加标回收率范围97.5%~105.0%,精密度小于2.0%。结果表明,方法操作简单、重现性好、准确度高,可为牛乳中A1 β-酪蛋白和A2 β-酪蛋白的进一步研究和应用作技术参考。

Based on the existing detection method data,this detection method improved the separation effect of A1β- Casein and A2β- casein by changing the column temperature and gradient elution conditions,so as to better analyze the content of A1β- Casein and A2β- casein in dairy products. In this assay,guanidine hydrochloride and dithiothreitol were used to denature β-caseinthe selection of mobile phase B（acetonitrile）,A（0.1 % TFA aqueous solution）,gradient elution,flow rate 0. 5 mL/min,reversed-phase liquid chromatography column,column temperature 50 ℃,214 nm detection.The method can effectively separate A1β-casein and A2β-casein,and the peak time was stable. A1β-casein in 0.16~1.65 mg/mL concentration range showed a good linear relationship,regression equation y=1.25×106x-1.44x105,R2=0.9985,R=0.9992,the RSD of precision was less than 2.0%,the range of recovery rate were 96.4%~105.0%.A2 β-casein in 0.34~3.35 mg/mL concentration range showed a good linear relationship,regression equation y=3.16×106x-3.16×105,R2=0.9988,R=0.9994,the RSD of precision was less than 2.0%,the range of recovery rate were 97.5 %~105.0 %. The results showed that the method was simple,reproducible and accurate. It can be used as a technical reference for further research and application of A1β-casein and A2β-casein in dairy products.