Sulfites are well-known additives in foods and beverages used to extend shelf life and preserve colors. Such properties have led to the broad usage of sulfites in a range of foodstuffs like fruits, cereals, vegetables, seafood, juices, alcoholic and non-alcoholic (soft) beverages, and in some meat products. The term «sulfites» describes a group of molecules that include sulfur dioxide (SO2) and chemically related molecules like sodium sulfite (Na2SO3), sodium bisulfite (NaHSO3), or sodium metabisulfite (Na2S2O5).
Sulfite intake has been correlated with several adverse reactions, and therefore sulfites are included in the FAO/WHO Codex Alimentarius list. Labelling sulfite content in foods and beverages is necessary when the total concentration exceeds 10 mg/kg. Metrohm ion chromatography allows the reliable measurement of sulfite in different matrices using either conductivity or amperometric detection. The inclusion of automated sample preparation and cleaning steps with Metrohm instrumentation saves additional analyst time and helps increase sample throughput.
Learn more about the optimized methods for simpler sulfite determination!
This free white paper outlines the chemical properties of sulfite in foods and the official regulations concerning this widely used additive, it explains historical determination methods such as the Monier-Williams method and their disadvantages, and it gives a detailed overview of two optimized sulfite determination methods (IC with amperometric and conductivity detection).