提出了食品中维生素D2和维生素D3的高效液相色谱-串联质谱分析方法。食品样品经氢氧化钾皂化后乙醚萃取,所得有机相经无水硫酸钠除水后蒸发至干。用1 mL乙醇溶解后经Agilent Zorbax XDB C18色谱柱(2.1 mm×50 mm,3.5 μm)分离,用甲醇-10 mmol·L-1乙酸铵溶液(90+10)的混合溶液洗脱,采用电喷雾正离子模式多反应监测。维生素D2和维生素D3的线性范围均为50~500 μg·L-1,检出限(3S/N)均为10 μg·L-1。方法应用于测定奶粉和酸酸乳中维生素D2和维生素D3,回收率在76.8%~83.9%之间。

HPLC-MS/MS was applied to the determination of vitamin D2 (VD2) and vitamin D3 (VD3) in food. The sample was saponifed with KOH and extracted with ethyl ether, and the organic phase obtained was dehydrated with anhydrous sodium sulfate and evaporated to dryness. The residue was dissolved with 1 mL of ethanol and used for HPLC-MS/MS determination, using Agilent Zorbax XDB C18 column (2.1 mm×50 mm, 3.5 μm) as chromatographic column, and a mixture of methanol and 10 mmol·L-1 ammonium acetate solution (mixed in the ratio of 90 to 10 by vol.) as mobile phase. Positive electrospray ionization as well as multiple reaction monitoring mode was used in the detection. Linearity ranges of VD2 and VD3 were found same between 50-500 μg·L-1 with their detection limits (3S/N) of 10 μg·L-1. The proposed method was used for the determination of VD2 and VD3 in milk powder and sour milk, giving values of recovery in the range of 76.8%-83.9%.