超高效液相色谱串联质谱法测定婴儿奶粉中的维生素B_(12)

建立了超高效液相色谱串联质谱法测定婴儿奶粉中维生素B12的方法。采用三氯乙酸沉淀蛋白质,HLB固相小柱吸附净化提取液中的维生素B12,以50%的甲醇洗脱,吹去甲醇后定容测定,色谱柱为ACQUTITY UPLC BEH C18柱,以甲醇–10 mmol/L乙酸铵水溶液为流动相梯度洗脱,MRM模式,定量离子为m/z 678.3/147.2。在优化条件下,线性范围为0.5~200μg/L,相关系数(r)为0.999 3,检出限为0.3μg/kg,回收率为88.3%~92.9%,测定结果的相对标准偏差小于5%(n=6)。方法具有样品处理简单、灵敏度高、重现性好、分析时间短等优点,可以作为实验室常规测定婴幼儿奶粉中维生素B12的方法。

Determination of Vitamin B12 in Infant Milk Powder by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

An ultra performance liquid chromatography-tandem mass method was developed to determinate vitamin B12 in infant milk powder. Protein was precipitated by trichloroacetic acid. Vitamin BL2 was adsorbed and purified by HLB solid phase extraction cartridges and eluted with 50% methanol. The determination was executed in an ACQUTITY UPLC BEH Ct8 column after methanol blown away. The optimal conditions were as follows： mobile phase was methanol- 10 mmol/L ammonium acetate water solution, gradient elution, MRM method, quantitative ion was m/z 678.3/147.2. Under the optimal conditions, the calibration curve was linear in the range of 0.5-200 μg/L with correlation coefficient（r） of 0.999 3 and the detection limit of 0.3 μg / L. The spiked recoveries were in the range of 89.8%-92.9%. The relative standard deviation of determination results was less than 5%（n=6）. The method has advantages of easy sample handling, high sensitivity, good reproducibility and short analysis time and it can be used as routine method for measuring vitamin B12 of infant milk powder in Lab.