RESUMO
In this work, simple, sensitive and accurate zero-order and derivative spectrophotometric methods have been developed for the determination of amprolium hydrochloride and ethopabate in admixture in veterinary premixes. The first method was based on the free solubility of the low constituent, ethopabate, in chloroform and the absorbance was measured at 267 mn. On the other hand, amprolium hydrochloride in the residue left was dissolved in 0.1 M hydrochloric acid and its absorbance was measured at 248 mn. The second method depended upon extracting the two drugs from their formulations using 0.1 M hydrochloric acid and the amplitude of the second derivative was measured at 279 nm for amprolium hydrochloride analysis and the amplitude of the first derivative of the valley was measured at 315 nm for ethopabate. These two methods allowed the simultaneous assay of amprolium hydrochloride and ethopabate in chicken feed in much shorter analysis time with good accuracy and precision