After reviewing the literature upon the subject, the author observes :—It is apparent that the determination of sulphur dioxide in most foods, in the amounts in which it is usually present as a preservative, does not present any special difficulties. When simple titration methods, either direct or after distillation, cannot be applied, distillation into bromine, iodine, or hydrogen peroxide solution, followed by gravimetric determination as barium sulphate, will always give accurate results, provided that certain precautions are taken. The most important points are (i) to ensure that the whole of the sulphur dioxide has been separated from combination with aldehydes, sugars, etc., and has been driven over into the distillate, (ii) to prevent oxidation of sulphur dioxide during distillation, and (iii) to correct the results for volatile sulphur compounds oxidized to sulphuric acid in the distillate.
MCB UP Ltd
Copyright © 1927, MCB UP Limited