高效液相色谱检测乳制品中的乳铁蛋白含量

HPLC Determination of Lactoferrin in Dairy Products

目的:借助高效液相色谱法测定乳制品中乳铁蛋白。方法:先通过额外加入的二价铁离子使乳铁蛋白的构型更利于沉淀。然后用体积分数60%乙醇溶液沉淀蛋白除去糖分,再用醋酸盐缓冲液提取乳铁蛋白并分离掉酪蛋白,最后用高效液相色谱检测,采用LiChrosorb RP-C18色谱柱,在质量浓度0.1g/100mL的三氟乙酸溶液协助下,甲醇与水线性梯度洗脱。结果:乳铁蛋白的线性范围是0.4～2mg/mL(R2=0.9980),平均回收率95.4%。结论:此方法可以用于乳制品中乳铁蛋白的测定。

A HPLC method was developed for the determination of lactoferrin in dairy products. Lactoferrin was easier to precipitate by the introduction of additional ferrous ion and 60% ethanol solution was added to precipitate proteins for removing carbohydrates. The precipitate, whose main composition was lactoferrin, was extracted with acetic acid buffer to remove casein impurity prior to HPLC analysis. The chromatographic separation was achieved on a LiChrosorb RP-C18 column using single 0.1 g/100 mL TFA as mobile phase A and a mixture of 98 % methanol and 0.1 g/100 mL TFA as mobile phase B and linear gradient elution mode was used. This method exhibited a good linearity over the concentration range of 0.4 to 2 mg/mL for lactoferrin in dairy products （R^2 = 0.9980）, and the average recovery for lactoferrin at five spike levels was 95.4%.