Both primary and secondary amines may be readily labelled with the 9-fluorenylmethoxy carbonyl group by the reaction with 9-fluorenylmethyl chloroformate (FMOCCI). The reaction proceeds rapidly under alkaline aqueous conditions, allows for simple elimination of excess reagent by partitioning, improves chroatographic resolution of amino acid-like compounds by anion exchange liquid chromatography and introduces a fluorophore with a large quantum yield which is essentially unaffected by solvent-solute interactions.