Studies on the correlation between structure and adsorption of sulfonamide compounds

The objects of this study were to find a relationship between structure and adsorption behaviour of sulfonamide compounds and compare their adsorption behaviours towards different experimental factors such as pH, temperature of the adsorption medium and addition of aliphatic alcohols to the adsorption medium. For this purpose four sulfonamides viz., sulfanilamide (S), sulfapyridine (SD), sulfadiazene and sulfamethoxazole (SM) were selected and adsorption experiments were carried out at identical experimental conditions. The study of concentration effect ((2.0–30.0)×10−3 mol l−1) and kinetics of the adsorption provided ideas about the adsorption characteristics of the four compounds and enabled in evaluating the adsorption isotherms, mode of adsorption, adsorption coefficient, rate constants of adsorption and desorption and surface coverages. Study of pH effect revealed that adsorption of S, SD and SM showed maxima at pH 9.0 while for SP the maximum was found at pH 3.0. The results obtained helped in formulating mechanisms of interaction between sulfonamide compounds and alumina surfaces.