Author: RPW Scott
Book:Principles and Practice of Chromatography
Section:Principles Applications Liquid-Chromatography b--blockers
developed by Yang et al. [14] developed and involved the synthesis of their fluorescent derivatives, which were formed by reacting them with an electrophilic fluorogenic reagent, 4-(N-chloroformethyl-N- methylamino-7-N- N–dimethylaminosulfonyl-2, 1, 2–benzoxydiazole (DBD- COCl). These derivatives show intense fluorescence at long excitation wavelengths (450Ex and 560Em nm) and thus significantly reduce the level of detection. It was found that Propranolol, Metoprolol and Atenolol, three very commonly used b blockers, reacted directly with reagent forming 1:1 adducts by reaction with the secondary amino group of the b-blockers. The DBD-COCl reagent reacted readily with the drugs under mild conditions, with no catalyst, and the reaction was relatively fast and was complete in about 5 min. The initial separation was carried out on a TSKgel ODS- 80T column, 15 cm long, 4.6 mm I.D., packed with 5 mm particles. The solvent gradient used to




