离子色谱法检测乳粉中的低聚半乳糖

Determination of Galactooligosaccharides in Milk Powder by Ion Chromatography

建立乳粉中低聚半乳糖(galactooligosaccharides,GOS)的离子色谱检测方法。采用乙腈沉淀样品中的蛋白质,用乙腈-水提取GOS,通过C_(18)柱或RP柱净化,去除杂质,经离子色谱仪四元梯度泵洗脱,电化学脉冲安培检测器检测。结果表明:本方法标准曲线在10～300?μg/mL范围内具有良好线性,样品重复测定结果稳定;加标量为500～2?000?mg/100 g时,回收率范围为82.1%～98.0%;方法前处理操作简单,检测结果准确,适用于乳粉样品中GOS含量的测定。

In this paper, an ion chromatography method for the determination of galactooligosaccharides(GOS) in milk powder was established. The protein in the sample was precipitated by acetonitrile, and GOS was extracted with acetonitrilewater and purified using a C18 column(or RP column) to remove impurities. The analyte was separated using an ion chromatograph equipped with quaternary gradient pumps and detected with a pulse amperometric detector. The calibration curve of this method had good linearity in the range of 10–300 μg/mL, and the results from repeated sample measurements were stable. The recovery rates from blank samples spiked at levels of 500–2 000 mg/100 g were 82.1%–98.0%. To sum up,this method required simple sample pretreatment and gave accurate results, and it could be suitable for the determination of the GOS content in milk powder samples.