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.

Human milk oligosaccharides (HMOs) are a group of complex glycans occurring in human breast milk that play important roles in the growth and development of infants. More than 200 distinct kinds of HMOs have been identified so far. The naturally occurring mixtures of HMOs in humans have different components and profiles that reflect the mother’s genetic makeup (e.g., Lewis blood type), duration of lactation, life style, diet and geographic region. A number of functions that may protect the health of breast-fed infants have been reviewed for HMOs. However, available information on the content and profiles of HMOs in human milk, especially among Chinese mothers, is limited. Therefore, further research on the relationship between the structure and functions of HMOs and a databank of HMOs from Chinese mothers are needed in order to establish a firm scientific basis and specific guidelines for improved infant formula in the future.