Physicochemical Properties and Method for Determination of Potassium Guaiacolsulfonate
Abstract The physicochemical properties of potassium guaiacol-4-sulfonate (I) and -S-suIfonate (II) have been investigated. Analyses of the X-ray diffraction patterns, infrared spectra, and thermogravimetric and differential scanning calorimetric curves showed that I occurs as crystals that are anhydrous or hydrated up to ⅔ mole (4.8%) and that II occurs as crystals that are anhydrous or dihydrated (13.5%). Solutions of I and II at various pH values showed almost the same UV spectra at <pH 6.0 but very different UV spectra >pH 7.0. Most commercially available potassium guaiacolsulfonate consists predominantly of potassium guaiacol-4-sulfonate (as determined by UVabsorption measurements and liquid chromatography).