复合固相萃取净化-液相色谱法测定奶粉中的维生素D

Determination of Vitamin D in Infant Formula Milk Powder by Composite Solid Phase Extraction Purification and Liquid Chromatography

建立婴幼儿配方奶粉中维生素D的复合固相萃取净化-液相色谱检测方法。样品经石油醚提取,复合固相萃取柱净化,C_(18)色谱柱(250 mm×4.6 mm,5μm)分离,采用液相色谱-紫外检测器进行测定,外标法定量。维生素D_(2)和维生素D_(3)在0.040,0.100,0.200,0.500,1.000和3.000 mg/L范围内线性关系良好,相关系数为0.9995和0.9996,方法定量限为0.015 mg/kg,方法检出限为0.0050 mg/kg。在0.015,0.050和0.75 mg/kg这3个质量分数水平下回收率在80.7%~98.5%之间,相对标准偏差(S_(RSD),n=6)在2.51%~7.93%之间。该方法操作简单、准确,具有较高的灵敏度,适合婴幼儿配方奶粉中维生素D含量的测定。

A method using liquid chromatography was developed for the determination of vitamin D in infant formula milk powder.The sample was extracted with petroleum ether followed by clean-up with composite solid phase cartridge.The liquid chromatography separation was performed on C_(18)column(250 mm×4.6 mm,5μm).It was determined by liquid chromatographyultraviolet detector and quantified by external standard method.The calibration curves of vitamin D_(2)and vitamin D_(3)showed a good linearity in the range of 0.040,0.100,0.200,0.500,1.000 and 3.000 mg/L,and the correlation coefficients were 0.9995 and 0.9996.The limits of detection of vitamin D_(2)and vitamin D_(3)were 0.0050 mg/kg.The limits of quantification were 0.015 mg/kg.The recoveries of milk powder spiked at 0.015,0.050 and 0.75 mg/kg were 80.7%-98.5%,and the relative standard deviations(S_(RSD),n=6)were 2.51%-7.93%.The method was simple,accurate and sensitive,and could effectively meet the quantitative determination of vitamin D in infant formula milk powder.