ABSTRACT
OBJECTIVE: To compare 3 different calculation methods in the determination of aspirin in the bicomponent (aspirin and salicylic acid) system. METHODS: Different concentrations of mixed standard solution of aspirin and salicylic acid were prepared and scanned under a wavelength ranged from 230nm to 350nm. The absorbabilities of the 2 constituents were recorded at 265nm, 295nm and 320.5nm, and the data were treated with Iso-absorption diplo-wavelength method, proximal multiplying factor coefficient method and SA concentration fractional approximate calculation method. The recoveries of aspirin were calculated. RESULTS:The recoveries of aspirin determined by 3 different methods were (99.11?1.68)%, (98.82?1.17) % and (96.23?4.10)%, respectively. CONCLUSION: The proximal multiplying factor coefficient method is stable with little fluctuation in determination results, which proved to be simple while effective for the determination of sample at a great quantity.