Abstract: A method for the determination of 14 human milk oligosaccharides (HMOs) in infant formula milk powder was established by hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The sample was deproteinized by ethanol precipitation and degreased by freezing prior to separation by HILIC. The analytes were detected by multiple reaction monitoring (MRM) and quantified by an external standard method. Under optimized conditions, all HMOs showed good linear relationships within their respective concentration ranges, with determination coefficients (R2) greater than 0.994. The average recovery rates from blank goat’s and cow’s milk powders at three spiked levels ranged from 90.3% to 109.2%, with relative standard deviation (RSD) in the range of 0.7%–9.7% (n = 6), and the limit of detection (LOD) between 0.002 and 0.048 μg/mL. The developed method is characterized by fast analysis speed, high sensitivity and good accuracy, and meets the requirements for the rapid detection of the 14 HMOs in infant formula milk powder.

Key words: infant formula milk powder; human milk oligosaccharides; hydrophilic interaction liquid chromatography-tandem mass spectrometry