Kinetics and determination of sulfa drugs via interaction with p-benzoquinone

Abstract

Eight sulfa drugs have been determined by applying a spectrophotometric method involving the interaction with excess p-benzoquinone, which was previously used successfully in the determination of aromatic amines. The colored products obtained display maximum absorption at λ 490–500 nm, depending upon the type of sulfa drug used, and E1%1 cm in the range 100–280. The reaction proceeded kinetically as a pseudo-first-order reaction. The activation parameters have been calculated and a relevant reaction mechanism has been suggested.