4-(N-Hydrazinoformylmethyl-N-Methyl)-Amino-7-N,N-Dimethylaminosulphonyl-2,1,3-Benzoxadiazole (DBD-CO-Hz) as a Precolumn Fluorescence Derivatization Reagent for Carboxylic Acids in High-Performance Liquid Chromatography

A new fluorescent reagent for carboxylic acids, 4‐(N‐hydrazinoformylmethyl‐N‐methyl)amino‐7‐N,N‐dimethylaminosulphonyl‐2,1,3‐benzoxadiazole (DBD‐CO‐Hz) was synthesized and its applicability as a precolumn derivatization reagent in high‐performance liquid chromatography (HPLC) was examined. DBD‐CO‐Hz reacted with saturated fatty acids in the presence of a condensing agent, 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC) and pyridine at room temperature for 30 min to give fluorescent products. The reaction solution was subjected to a reversed‐phase HPLC and detected fluorometrically at a wavelength of 550 nm with an excitation of 440 nm. The detection limits of the derivatives were at low fmol range on column.