High-speed liquid chromatographic analysis of dapsone and related compounds

A nonaqueous solvent absorptive support system and an aqueous solvent reversed-phase support liquid chromatographic system for analysis of dapsone and related compounds were investigated. The absorptive support system was more suitable for analysis of dapsone in raw materials, formulations, and tissue residues. The suitability was judged by the relative selectivity, efficiency, precision, and sensitivity of the systems. The adsorptive support system was used for the analysis of trace amounts of raw material impurities and dapsone metabolites. Coupling fluorometric detection to the chromatographic system yielded a 10-pg on-column detection limit for dapsone; the UV detection limit was 250 pg.