Analysis for total sulfite in foods by using rapid distillation followed by redox titration

• Published in: Journal of the Association of Official Analytical Chemists Vol. 69; no. 5; p. 827
• Main Authors: DeVries, J W, Ge, H, Ebert, F J, Magnuson, J M, Ogawa, M K
• Format: Journal Article
• Language: English
• Published: United States 01-09-1986
• Subjects: Food Additives - analysis; Food Analysis; Indicators and Reagents; Methods; Oxidation-Reduction; Sulfites - analysis
• ISSN: 0004-5756
• DOI: 10.1093/jaoac/69.5.827

A rapid and accurate analysis for total sulfite as sulfur dioxide has been developed for foods and food products. The method, which combines a selective distillation cleanup procedure with the selective redox titration of sulfite ion by iodine, has been applied to a variety of foods and food products over a period of time with no significant interference encountered in any matrixes other than garlic and leeks. For the foods analyzed, the method typically shows a detection limit of 10 ppm, a relative standard deviation of 7.5% (compared with 10.4% for similar matrixes by the Monier-Williams method), and recoveries of 97.9 +/- 6.4%. Comparison of results for this method with those obtained using the Monier-Williams method showed a mean value for the distillation/titration method of 241 ppm compared with 242 ppm for the Monier-Williams method. A correlation of 0.991 and odds of a difference between methods of 10.7% (Student's paired t-test (1-alpha) X 100) were obtained for those matrixes where no interferences were encountered with either method.