A method for a structural characterization of polysaccharides, comprising steps of characterizing a polysaccharide by physical measurements comprising a determination of a mass of the polysaccharide by means of mass spectrometry, a further determination of a rotationally averaged cross section of the polysaccharide by means of ion mobility spectrometry, and an infrared spectrum of the polysaccharide by means of cryogenic, messenger-tagging IR spectroscopy.