3-Aminoquinoline was used: . in liquid matrix for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for glycopeptides, carbohydrates and phosphopeptides . in liquid matrix during novel glycan-labeling method for quantitative profiling of N-glycan by MALDI-MS analysis . as derivatizing reagent for MALDI-MS analysis of oligosachharides 3-Aminoquinoline was used: . in liquid matrix for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for glycopeptides, carbohydrates and phosphopeptides . in liquid matrix during novel glycan-labeling method for quantitative profiling of N-glycan by MALDI-MS analysis . as derivatizing reagent for MALDI-MS analysis of oligosachharides