Structural characterisation of N-linked glycan mixtures by precursor ion scanning and tandem mass spectrometric analysis

2-Aminoacridone (2-AMAC) labelled N-linked glycan pools were analysed directly by a hybrid quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-Tof) in the precursor ion scanning and tandem mass spectrometry (MS/MS) modes. The use of a precursor ion scanning strategy on this instrument provides a rapid and sensitive method of screening glycan mixtures, without prior separation by chromatographic methods. It allows facile and preliminary characterisation of glycans into different classes, for example, high-mannose or complex glycans. Preliminary sequencing information for each glycan is obtained in the initial precursor ion scanning mode, but further sequencing information of selected glycans can be obtained using the MS/MS mode.