Abstract: A pre-column derivatization method for separating and analyzing oligosaccharides by high performance liquid chromatography-electrospray ionization ion-trap mass spectrometry (HPLC-ESI-MS/MS) was established by using aniline as reductive amination reagent. Under the optimized HPLC-ESI-MS/MS conditions, HPLC separation was carried out on an Elite RP C18 column (4.6 mm × 250 mm, 5μm) with a mobile phase made up of acetonitrile and ammonium acetate (10 mmol/L, pH 4.5) under gradient elution mode and ultraviolet detection was performed at 239 nm. Maltodextrin derivatives were successfully separated and analyzed by HPLC-ESI-MS/MS in a positive ion mode. Stable maltodextrin derivatives and easy post-treatment could be achieved by this method. Hence, we conclude that it has potential application prospects in separation and analysis of oligosaccharides in food matrixes.

Key words: aniline, high performance liquid chromatography-electrospray ionization ion-trap mass spectrometry, pre-column derivatization, oligosaccharides