N-(4-nitro-2,1,3-benzoxadiazoyl-7-yl)- N-methyl-2-aminoacetohydrazide (NBD-CO-Hz) as a precolumn fluorescent derivatization reagent for carboxylic acids in high-performance liquid chromatography

A new fluorescent reagent for carboxylic acids, N-(4-nitro-2,1,3-benzoxadiazoyl-7-yl)- N-methyl-2-aminoacetohydrazide (NBD-CO-Hz) was synthesized and its applicability as a precolumn derivatization reagent in high-performance liquid chromatography was examined. NBD-CO-Hz reacted with 2-arylpropionic acids (2-APAs), a group of non-steroidal antiinflammatory drugs (NSAIDs) in the presence of a condensing agent, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and pyridine at room temperature for 2 h to give fluorescent adducts. The reaction solution was subjected to a reversed phase or a chiral stationary phase HPLC and the derivatives were detected fluorometrically at a wavelength of 530 nm with an exitation of 475 nm. The detection limits were in the fmol range on column.