超滤离心净化-高效液相色谱法同时测定配方乳粉中的单糖、双糖和低聚果糖

Simultaneous determination of monosaccharides, disaccharides and fructo-oligosaccharides in milk powder by ultra-filtration clean up coupled with high performance liquid chromatography

目的采用超滤离心截留技术快速除杂,结合高效液相色谱仪,建立一种同时检测配方乳粉中7种糖类化合物(果糖、葡萄糖、蔗糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖)的分析方法。方法经实验优化,选用截留分子量3000的超滤离心管高速离心去除样品溶液中的蛋白质、核酸和多糖等大分子物质,以乙腈-水为流动相(75:25,v:v)等度洗脱,Luna氨基色谱柱分离,示差折光检测器检测。结果 7种目标分析物在0.15~10.0mg/m L范围内线性关系良好,相关系数大于0.999,方法检出限在0.039~0.087 g/100 g之间;当添加水平为0.50~2.0 g/100 g时,回收率在81.2%~105%之间,相对标准偏差(RSD,n=6)为1.1%~6.2%。结论该方法与国标方法的检测结果一致,且前处理简单、结果准确、回收率高,适合配方乳粉中7种单糖、双糖和低聚果糖的测定。

Objective To establish a simple and rapid method based on ultra-filtration clean up method and high performance liquid chromatography(HPLC) to determine 7 kinds of carbohydrate compounds(fructose, glucose, sucrose, lactose, kestose, nystose and 1F-fructofuranosylnystose) in milk powder. Methods Milk powder sample was dissolved by water, and then treated with ultra-filtration centrifugal molecular weight cut-off 3000 tube to remove protein, nucleic acid and polysaccharide macromolecular substances by high-speed centrifugation. The separation was performed on a Luna NH2 column with isocratic elution of acetonitrile: water(75:25, v:v)as the mobile phase. The analytes were determined by a refractive index detector(RID). Results Under the optimal conditions, the calibration curves were linear in the range of 0.15 to 10.0 mg/m L with correlation coefficients larger than 0.999. The limits of detection(LODs) were from 0.039 to 0.087 g/100 g. The mean recoveries for milk powder sample at three spiked concentration levels of 0.50~2.0 g/100 g were in the range of 81.2% to 105%, and the relative standard deviations(RSD) ranged from 1.1% to 6.2%(n=6). Conclusion This method is simple, rapid, and it is suitable for the identification and quantification of monosaccharides, disaccharides and fructo-oligosaccharides in milk powder.