Characterization of impurities in commercial lots of sodium saccharin produced by the Sherwin-Williams process. I. Chemistry.

Saccharin produced by the Sherwin-Williams process was analysed to determine the concentration and identities of impurities. Inorganic and ionic organic (water-soluble) impurities were not present above the detection limit of the methods used. Low levels (c. 10 ppm in total) of solvent-extractable organic impurities were detected and characterized using high-performance liquid chromatography, gas chromatography and combined gas chromatography-mass spectrometry. Over 50% of the total impurity content was identified, and most of the contaminants were found to be derived from the material (polyethylene bags) in which the saccharin was packed rather than from the saccharin production process. N-Methylsaccharin (0.15 ppm) and methyl anthranilate (0.05 ppm) were the predominant impurities related to the production process. Impurities derived from the packaging material included mineral oil, fatty acid amides and various plasticizers and antioxidants. No single impurity was present at a level above 1 ppm in the saccharin. The results of this study indicate that saccharin produced by the Sherwin-Williams process is a highly pure material.