超高效液相色谱-同位素稀释质谱法同时测定婴幼儿配方奶粉中10种水溶性维生素

Simultaneous determination of 10 kinds of water soluble vitamins in infant formula by ultra performance liquid chromatography–isotope dilution mass spectrometry

目的建立超高效液相色谱-同位素稀释质谱法(ultra performance liquid chromatography-isotope dilution mass spectrometry,UPLC-IDMS)同时检测婴幼儿配方奶粉中10种水溶性维生素(维生素B1、维生素B2、烟酸、烟酰胺、吡哆醇、吡哆醛、吡哆胺、泛酸、生物素、叶酸)的方法。方法样品用水溶解后,加入同位素内标,用1 mol/L盐酸溶液调节pH至1.7,再用1 mol/L NaOH溶液调节pH至4.5,经Agilent ZORBAX SB-AQ C18色谱柱(100 mm×3.0 mm,1.8μm)分离,正离子模式下以0.2%甲酸水溶液和甲醇-乙腈(4:6,V:V)为流动相,负离子模式下以水和甲醇-乙腈(4:6,V:V)为流动相梯度洗脱,采用电喷雾离子源,分别在正、负离子模式下进行多反应监测模式测定,内标法定量。结果10种水溶性维生素在10~5000ng/mL内具有良好的线性关系,相关系数(r^2)大于0.99,加标回收率为85.7%~115.8%,相对标准偏差为1.82%~9.67%。结论该方法简便、快速、灵敏、准确,可满足婴幼儿配方奶粉中水溶性维生素的检测要求。

Objective To establish a method for simultaneous determination of 10 water soluble vitamins(vitamin B1,vitamin B2,niacin,niacinamide,pyridoxin,pyridoxal,pyridoxamine,pantothenic acid,biotin,and folic acid)in infant formula by ultra performance liquid chromatography-isotope dilution mass spectrometry(UPLC-IDMS).Methods Samples were disolved in water and spiked isotope internal standard,the pH value was adusted to 1.7 by 1 mol/L HCl solution and then adjusted pH to 4.5 by 1 mol/L NaOH solution,then separated with Agilent ZORBAX SB-AQ C18 column(100 mm×3.0 mm,1.8μm)in gradient elution using 0.2%fomic acid solution and methanol-acetionitrile(4:6,V:V)as mobile phase at positive ionization mode,and using H2 O and methanol-acetionitrile(4:6,V:V)as mobile phase at negative ionization mode.Mass spectrometry data was acquired by multiple reaction monitoring(MRM)mode using electrospray ionization at both positive and negative ionization mode.The quantification analysis was carried out by internal standard method.Results The results showed a good linear calibration in the range of 10–5000 ng/mL with correlation coefficients(r2)above 0.99,the recoveries of 10 vitamins ranged from 85.7%to 115.8%,with relative standard deviations of 1.82%–9.67%.Conclusion This method is simple,rapid,sensitive and accurate,and can meet the determination requirements of water soluble vitamins in infant formula.