A new coumarin based fluorogenic derivatization reagent for labelling free carboxyl groups (Br-MOZC)

A new coumarin based bromomethyl fluorescent probe 4-bromomethyl coumarin[a,b-c,d]-oxazine-3 -one was synthesized as a fluorescent carboxylic acid derivatizing agent. The synthetic route is described, as well as its application for the determination of the model compound eta-butyric acid. The derivatization reaction was conducted in acetone using 18-crown-6 as catalyst. The derivatization solution was separated by high performance liquid chromatography on a reversed phase ODS C-18 column (150 x 4.6 nim i.d., 5 mum) with a mobile phase of acetonitrile and water (70: 30, v/v) at a flow rate of 1.0 mL/min. The excitation and emission wavelengths were set to 435 and 345 mn, respectively. The detection limit was determined to be below 10pg of the derivatized acid on the column. The probe has been used for the simultaneous determination of six aliphatic fatty acids.