在线固相萃取-高效液相色谱法快速测定奶粉中的维生素K1与维生素K2

Rapid determination of vitamin K1 and vitamin K2 in milk powder by online solid phase extraction-high performance liquid chromatography

中文关键词:  维生素K1  维生素K2  四烯甲萘醌  七烯甲萘醌  在线固相萃取  高效液相色谱法

英文关键词:vitamin K1  vitamin K2  menaquinone-4  menaquinone-7  online solid phase extraction  high performance liquid chromatography

中文摘要:

      目的 建立在线固相萃取-高效液相色谱法快速测定奶粉中维生素K1 (vitamin K1, VK1)、维生素K2 (vitamin K2, VK2)含量的分析方法。方法 1 g奶粉样品中加入3 mL 0.13 g/mL脂肪酶水溶液, 37℃恒温酶解脂肪, 并用氢氧化钾的水-异丙醇混合溶液定容至25 mL, 获得酶解液。使用在线固相萃取-高效液相色谱联用仪对酶解液进行自动化分析, 其中以甲醇:水=20:80 (V:V)作为上样溶剂, 甲醇作为清洗、除水溶剂, 10%四氢呋喃甲醇作为转移溶剂与液相色谱流动相, Eclipse Plus C18柱(150 mm×4.6 mm, 5 μm)作为分析柱, 经过锌粉还原柱(50 mm×4.6 mm, 70 μm)衍生, 采取荧光检测器进行检测, 外标法定量, 获得VK1、VK2含量。结果 VK1、四烯甲萘醌(menaquinone-4, MK-4)、七烯甲萘醌(menaquinone-7, MK-7)在0.002~0.100 μg/mL范围内线性良好; 检出限分别为0.12、0.14、0.19 μg/100 g, 方法定量限为0.37、0.46、0.58 μg/100 g。结论 该方法操作简便、快速、灵敏度高, 稳定性良好, 可作为婴幼儿奶粉质量控制、监督检查的快速检验方法。

英文摘要:

      Objective To establish an online solid phase extraction-high performance liquid chromatography method for rapid determination of vitamin K1 (VK1) and vitamin K2 (VK2) in milk powder. Methods The amount of 3 mL aqueous solution of lipase with the concentration of 0.13 g/mL was added to 1 g of milk powder sample, the fat was enzymatically hydrolyzed at 37℃, and the mixture of potassium hydroxide and water-isopropanol was reduced to 25 mL to obtain the enzymolysis solution. The enzymolysis solution was analyzed automatically by an instrument of online solid phase extraction combined with high performance liquid chromatography, the solution of methanol:water=20:80 (V:V) was used as the loading solution, and methanol was used as the cleaning and water removal solution, and 10% tetrahydrofurfuryl alcohol was used as the transfer solvent and liquid chromatography mobile phase, Eclipse Plus C18 column (150 mm×4.6 mm, 5 μm) was used as the analysis column, which was derived by the zinc powder reduction column (50 mm×4.6 mm, 70 μm). A fluorescence detector was used for detection, and the external standard method was used to quantify the content of VK1 and VK2. Results VK1, menaquinone-4 (MK-4) and menaquinone-7 (MK-7) were linear in the range of 0.002?0.100 μg/mL; the limits of detection were 0.12, 0.14, and 0.19 μg/100 g, respectively, and the limits of quantitation were 0.37, 0.46, and 0.58 μg/100 g. Conclusion This method is easy to operate, rapid, sensitive and stable, it can be used as a rapid test method for quality control and monitoring and inspection of infant milk powder.