Abstract
The infrared absorption spectra of sulphonamides, when compared with the spectra of Authentic Specimens, provide a simple and complete means of identification, provided the effects of polymorphism are excluded. Of 18 substances examined, twelve showed evidence of polymorphism. Limited solubility prevents the use of solution spectra, and specified solvent treatments, details of which are given, may therefore be necessary with these substances to ensure reproducible spectra.