1989 Volume 5 Issue 1 Pages 31-34
2-[p-(5, 6-Methylenedioxy-2H-benzotriazol-2-yl)]phenethylamine (MBPA; 1) and two related compounds (2 and 3) were synthesized as highly sensitive fluorescence derivatization reagents for carboxylic acids. We investigated the fluorescence characteristics and the chromatographic behavior of their benzamide derivatives produced by the reaction with benzoic acid. Among them, MBPA was found to be the best reagent for use in high performance liquid chromatography (HPLC). Thus it was applied to the determination of ibuprofen in human serum. MBPA reacted with ibuprofen in the presence of 2-bromo-1-ethylpyridinium tetrafluoroborate to give the corresponding fluorescent amide at room temperature. Linear relationships were found between the peak areas and the concentrations of ibuprofen in the range of 5-100ng/ml and 0.5-5ng/ml with relative standard deviations of 7.49% and 15.02%, respectively. The detection limit for ibuprofen in serum was 1.5pg per injection.