同位素稀释-超高效液相色谱-串联质谱技术检测婴幼儿配方奶粉中维生素D

Determination of Vitamin D in infant formula milk powder by isotope dilution-ultra high performance liquid chromatography-tandem mass spectrometry

目的建立婴幼儿配方奶粉中维生素D的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。方法样品经过低温皂化,正己烷萃取,Silica固相萃取柱净化,氮吹后用甲醇定容,使用安捷伦BEH C_(18)柱分离,采用电喷雾电离源(ESI)、正离子扫描和多反应监测(MRM)模式检测维生素D_2和维生素D_3含量,同位素内标定量。结果维生素D_2和D_3分别在10～200μg/L和1.5～200μg/L范围内线性关系良好(r>0.995),检出限分别为10μg/kg和1.5μg/kg,定量限分别为25μg/kg和4.5μg/kg。加标平均回收率分别为97%～118%和87%～102%,相对标准偏差为2.36%～7.37%。结论建立的方法简单、快速、重复性好,可同时测定不同基质婴幼儿配方奶粉中维生素D_2和D_3含量,满足日常监测要求。

Objective To establish a method for determination of vitamin D in infant formula milk powder by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Methods Samples were treated by low temperature saponification,extracted by hexane,purified by silica solid phase extraction column,dried by nitrogen and dissolved in methanol.The Agilent BEH C18 column was used for separation,the electrospray ionization(ESI)and positive ion scanning together with multiple reaction monitoring(MRM)mode were used to analyze vitamin D2 and vitamin D3 concentration.Isotope internal standard method was used for quantification analysis.Results For vitamin D2 and D3,the linear relationship was good in concentration ranges of 10-200μg/L and 1.5-200μg/L,respectively,with both correlation coefficient(r)greater than 0.995.The limits of detection(LODs)of Vitamin D2 and D3 were 10μg/kg and 1.5μg/kg,respectively,and the limits of quantification(LOQs)were 25μg/kg and 4.5μg/kg,respectively;the average spiked recovery rates were in the range of 97%-118%and 87%-102%,respectively,and the relative standard deviations were 2.36%-7.37%.Conclusion The established method is simple,rapid and reproducible.It can simultaneously determine the concentration of vitamin D2 and D3 in infant formula milk powder samples with different matrix and satisfy the daily monitoring requirements.