高效液相色谱-示差折光法测定保健食品中的低聚木糖

目的建立高效液相色谱-示差折光测定保健食品中的低聚木糖(以木糖计)的方法。方法样品经水提取,在沸水浴中用硫酸水解,用氢氧化钠调成中性后以乙腈+水(70+30)为流动相,通过氨基柱(4.6 mm×250 mm,5μm)分离后用示差折光检测器检测,同一样品在水解前后木糖含量的差值即为样品中低聚木糖的含量。结果被测组分浓度(0.30～4.50 mg/ml)与峰面积线性关系良好(r=0.999 9);相对标准偏差1.86%～3.80%(n=6),在固体保健食品中加标回收率为90.3%～93.6%和92.6%～98.3%;在液体保健食品中加标回收率为89.0%～97.0%和91.0%～96.0%。结论本方法快速、灵敏、重现性好,适用于测定保健食品中的低聚木糖。

Determination of xylo-oligosaccharides in health foods by HPLC with differential refractive index detector

Objective To develop an analytical method for the determination of xylo-oligosaccharides in health foods by high performance liquid chromatography with differential refractive index detector.Methods The samples were extracted and then hydrolyzed(4.6 mm×250 mm,5 μm) with sulfuric acid solution in boiling water bath;neutralized with sodium hydroxide solution;separated on a NH2 column with a mixture of acetonitrile-water(70+30,V/V) as mobile phase;detected by refractive index detector at a flow rate of 1.0 ml/min.Results There was a good linearity of the calibration curve between the peak area and the mass concentration of xylose in the range of 0.30-4.50 mg/ml(r=0.999 9);The relative standard deviations were 1.86%-3.80%(n=6);the recoveries were 90.3%-98.3 % in solid health foods and 89.0%-97.0% in liquid foods.Conclusion This method is found to be simple,rapid,precise and accurate.Therefore,the method can be successfully used for the determination of xylo-oligosaccharides in health foods.