高效液相-蒸发光散射测定奶制品中的动物水解蛋白

目的：建立高效液相色谱- 蒸发光散射检测法(HPLC-ELSD)测定奶制品中动物水解蛋白含量的方法。方法：奶制品用酸水解法进行处理。采用色谱柱：Shim-pack C18(4.6mm × 250mm，5μm)，流动相 3.8mmol/L 七氟丁酸溶液- 甲醇(8:2，V/V)，流速 1.0mL/min，ELSD 漂移管温度 50℃，载气压力 350kPa，进样量10μL，测定奶制品中羟脯氨酸(Hyp)。结果：在优化条件下，羟脯氨酸的线性范围为10～1000μg/mL，r=0.99993(n=5)，最低检出限为5μg/mL。动物水解蛋白的平均回收率为99.83%，RSD 为2.77%。结论：本法不需对样品进行衍生，操作简单，灵敏度高，结果准确，可用于羟脯氨酸的分离检测。

Determination of Hydrolyzed Animal Protein in Dairy Products by High-performance Liquid Chromatography with Evaporative Light Scattering Detection

Objective: To develop a high-performance chromatographic method with an evaporative light scattering detector (ELSD) for the quantified determination of hydrolyzed animal protein in dairy products. Methods: Acidic hydrolysis was employed for sample pretreatment. The chromatographic column used for analyte separation was Shim-pack C18 (4.6 mm × 250 mm, 5μm) with 3.8 mmol/L heptafluorobutyric acid/methanol (8:2, V/V) as the mobile phase at a flow rate of 1.0 mL/min. The ELSD drift temperature was set at 50 ℃, and the carrier gas pressure at 350 kPa. The sample load of 10μL was adopted. The content of hydroxyproline determined under these conditions was used to characterize the level of hydrolyzed animal protein in samples. Results: The developed method displayed good linearity over the concentration range of 10 to1000μg/mL, with a determination coefficient of 0.99993 (n = 5) and its detection limit was 5μg/mL. The average spike recovery for hydroxyproline was 99.83%, with 2.77% RSD. Conclusion: This method without sample derivatization has the benefits of simplicity of operation as well as high sensitivity and accuracy, and is applicable for the determination of hydroxyproline.