A new fluorogenic reagent, 2-methyl-3-oxo-4-phenyl-2,3-dihydrofuran-2-yl acetate, has been developed for the analysis of primary amines and aminated carbohydrates by means of HPLC, CE, and MALDI/MS. Peptides at 1 pmol (2 x 10(-7) M) levels were successfully labeled and analyzed through CE. The fluorescent derivatives have good stability in both acidic and basic solutions, making their further manipulation and structural analysis possible. The derivatives can be analyzed in reversed-phase HPLC due to the hydrophobic nature of this fluorescent tag. Characteristic elution intervals between the diastereomeric peaks of the chiral peptide derivatives may be used in structural verification. The labeled peptides and neutral oligosaccharides are also readily detectable through MALDI/MS in its positive mode.