Revision of IFU Method 7a

Determination of Sulphur Dioxide

IFU Method 7a – The determination of total sulphur dioxide has been revised and is available in the catalogue of methods which can be accessed via the IFU website www.ifu-fruitjuice.com.

The revision includes an addendum for the determination of SO₂ is via ion chromatography. This is useful when a confirmation of very low concentrations is needed or when false positive results must be ruled out. This can be the case for example in vegetable juices from Brassica (cabbage) which contains high levels of endogenous sulfur compounds. An analysis on sulfate from the solution of the first receiver flask can be performed using this procedure.