Sorption-spectroscopic determination of dimedrol in the form of ionic associates with anionic azo dyes

The sorption of ionic associates of acidic azo dyes – sulfonazo and Congo red with diphenhydramine on polyurethane foam is studied depending on pH, phase contact time, and component ratio. A method for determining diphenhydramine in medicinal products is developed based on its sorption in the form of ion associates with dyes and subsequent detection on the sorbent surface using diffuse reflectance spectroscopy.