Lactoferrin is an iron-binding cationic glycoprotein (pI = 8.7) beneficial for mammal health, especially udder and milk preservation. A new simple two-step method of quantification was developed. Lactoferrin in 1 mL of bovine skim milk was first adsorbed onto 100 mg of macroporous sulfonated-resin at pH 6.8 by rotary stirring for 90 min at 20–25 °C. After washing the resin, lactoferrin was desorbed using 1 mL of 2 M NaCl containing phenylalanine as a dilution marker, then fully resolved and quantified by RP-HPLC at 220 nm using a wide-bore C4 silica column. This robust, inexpensive and flexible method improves selectivity (no protein interference) and sensitivity compared to previous HPLC methods. In-laboratory validation demonstrated its linearity (25 to 514 µg Lf mL⁻¹), accuracy (110 to 98% recovery), and precision (<4%), which were comparable to immuno-based methods. The results for individual raw cow’s milk were strongly correlated with results using an ELISA test.

乳铁蛋白是一种铁结合阳离子糖蛋白（pI = 8.7），对哺乳动物健康特别是乳房和乳汁的保存有益。开发了一种新的简单的两步定量方法。首先通过在20–25°C下旋转搅拌90分钟，将1 mL牛脱脂乳中的乳铁蛋白吸附到100 mg pH 6.8的大孔磺化树脂上。洗涤树脂后，使用1 mL含苯丙氨酸的2 M NaCl作为稀释标记物解吸乳铁蛋白，然后使用宽口径C4硅胶色谱柱在220 nm下通过RP-HPLC完全解析和定量。与以前的HPLC方法相比，这种健壮，廉价且灵活的方法提高了选择性（无蛋白质干扰）和灵敏度。实验室内验证表明其线性（25至514 µg Lf mL ^-1），准确度（回收率110％至98％）和精密度（<4％），可与基于免疫的方法相媲美。单个生牛奶的结果与使用ELISA测试的结果密切相关。