本研究建立了超高效液相色谱-串联质谱法测定特殊医学用途婴儿配方食品中生物素含量的分析方法。样品经0.2 mol/L磷酸121 ℃水解30 min提取，并通过生物素免疫亲和柱净化后，采用Acquity UPLC BEH C18（100 mm×2.1 mm，1.7 μm）色谱柱进行分离，以乙腈-0.1%甲酸溶液为流动相进行梯度洗脱，经电喷雾电离串联质谱在多离子反应监测（MRM）模式下进行测定，内标法定量。在最优化条件下，生物素在0.50~50.00 ng/mL范围内线性关系良好（R2=0.9986），方法检出限为0.75 μg/100 g。特殊医学用途婴儿配方食品中生物素相对标准偏差在0.42%~4.77%之间，不同添加浓度回收率为97.27%~102.06%。该方法具有样品处理操作简单，灵敏度高，分析周期短等优点，可以满足特殊医学用途婴儿配方食品中生物素含量的测定，可为企业质量控制和政府监管提供有力的技术支撑。

In this study, an ultrahigh liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of biotin content in infant formulas for special medical purposes. Samples were hydrolyzed with 0.2 mol/L phosphoric acid at 121 ℃ for 30 min before extraction and purification by a biotin immunoaffinity column. The analyte was separated on an acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) and eluted with the mobile phase of acetonitrile -0.1% formic acid in a gradient mode. Analyses were performed by the MS/MS system with electrospray ionization (ESI) in a multiple-reaction monitoring (MRM) mode and an internal standard. Under the optimized conditions, a good linear relationship was obtained for biotin in the range of 0.50~50.00 ng/mL (R2=0.9986), with a detection limit of 0.75 μg/100 g. The relative standard deviation of the biotin in the infant formulas for special medical purposes was 0.42%~4.77%, with the recoveries of the spiked samples at three levels were 97.27%~102.06%. The method has several advantages (simple sample processing, high sensitivity and short analysis cycle), therefore, can meet the requirements for determining the biotin content in infant formulas for special medical purposes, providing strong technical support for enterprise quality control and government supervision.

国家食品安全关键技术研发重点专项（2017YEC1601600）；山东省重点研发计划项目（医用食品专项计划）（2019YYSP020）