浊点萃取-高效液相色谱法测定牛奶中的双酚A和壬基酚

摘要

目的：建立浊点萃取-高效液相色谱相结合检测牛奶中双酚A和4-n-壬基酚的分析方法。方法应用浊点萃取(CPE)对牛奶中的双酚A和4-n-壬基酚进行萃取富集。研究确立了牛奶体积为10 mL时,冰乙酸体积为200µL,无水硫酸钠质量为0.900 g,离心参数为9917.355 g(10000 r/min)、8℃、10 min的最佳破乳条件；最佳浊点萃取条件为：Tween 20的浓度为100 g/L,无水硫酸钠的质量为0.020 g,正丁醇的体积为200µL,平衡温度为60℃,平衡时间为30 min。结果双酚A在0.05-2.00 mg/L,壬基酚在0.1~5.00 mg/L范围内呈良好的线性关系,线性相关系数均大于0.999,双酚A的加标回收率在85.60~91.20%之间,壬基酚在71.30~73.30%之间, RSD为3.42~9.85%,方法的检出限分别为7.36μg/kg、93.19μg/kg。结论该方法具有有机试剂用量少、灵敏度高、绿色环保以及操作简单等特点,对于牛奶中的双酚A和壬基酚有着良好的检测效果。%Objective To establish a method for determination of bisphenol A(BPA) and 4-nonylphenol (4-NP) in milk by cloud point extraction (CPE) and high performance liquid chromatography (HPLC). Methods BPA and 4-NP in milk were extracted and preconcentrated by a pretreatment method known as CPE. The best de-emulsification conditions were: 200 μL glacial acetic acid and 0.900 g Na2SO4, centrifugation at 9917.355 g (10000 r/min), 8 ℃, 10 min, with the volume of milk being 10 mL. The optimal cloud point extraction conditions were: 100 g/L concentration of Tween 20, 0.20 g Na2SO4 and 200 μL n-butyl alcohol, equilibrated at 60 ℃ for 30 min. Results BPA and 4-NP had a good linear relationship in range of 0.05 to 2.00 mg/L and 0.1 to 5.00 mg/L, respectively. The linear correlation coefficients were above 0.999. Recoveries of Bisphenol A and 4-NP were between 80.5%~96.6%and 70~84%with relative standard deviations of 3.42 to 9.85%. The limit of detection was 7.36μg/kg and 93.19μg/kg, respectively. Conclusion This method has the advantages of less organic solvent consumption, high extraction efficiency, environmentally friendly and simple operation. It is efficient and reliable for the determination of BPA and 4-NP in milk.