A number of methods have been developed for sulfite
determination, which may be classified according to the compounds
measured. One approach is to acidify the sample,
then determine the amount of sulfur dioxide gas formed
using gas chromatography [5]. Alternatively, sulfur dioxide
can be oxidized to sulfuric acid using hydrogen peroxide,
followed by an acid–base titration [6]. A typical example
of the titration approach is the Monier–Williams method,
which is recommended by the Association of Official Analytical
Chemists (AOAC)