NBD fluoride (4-Fluoro-7-nitrobenzo-2-oxa-1,3-diazole) is similar to NBD chloride except that the former is much more reactive toward amines. Both reagents are nonfluorescent until they react with primary or secondary amines to produce a fluorescent product. NBD chloride and NBD fluoride have been extensively used as derivatizing reagents for chromatography analysis of amino acids and low molecular weight amines. &lamba;Ex/&lamba; Em (MeOH) = 465/535 nm (for reaction product with primary amines); 485/540 nm (for reaction product with secondary amines) Yellow solid soluble in DMF Store at -20°C and protect from light C6H2FN3O3 MW:183