Setschenow coefficients for caffeine, theophylline and theobromine in aqueous electrolyte solutions

Abstract

Setschenow coefficient measurements have been made on methylated xanthines (caffeine, theophylline and theobromine) in several inorganic and organic aqueous salt solutions at 298 K. In general, the order of salting effect is similar for the three solutes and can be rationalized as a consequence of structural salt–water interactions. Scaled particle theory and the Cross and McTigue equation have been employed to compare theoretical and experimental salting constants.