Determination of Sulphur Dioxide in Foods by Ion Chromatography

Sulphur type compounds are used as preservatives as they release SO2 in food. Legislation restricts the use of these additives due to the toxic effects they may have on humans. The Tanner method was modified by replacing the traditional distillation apparatus with a Buchi distillation unit which shortens the extraction time considerably. The final titration was replaced with a chromatographic separation followed by conductivity detection for sulphate ion facilitating a more sensitive and rapid analysis.
The method was then validated with a linear range from 6 mg to 2500mg/Kg SO2 , the limit of Quantitation was matrix dependent ranging from 4 to 6mg/Kg. This method can be used for the determination of sulphur dioxide levels in food and beverages to verify that levels conform to legislative requirements.
Presenter: Noel Finn (Executive Analytical Chemist, Public Analyst Laboratory (Cork, Ireland))
I am presently employed as an Executive Analytical Chemist with the Public Analyst Laboratory in Cork. The Public Analyst Laboratory works in association with the FSAI (Food Safety Authority Of Ireland) ensuring that food produced, distributed and marketed in Ireland complies with food safety standards and legal requirements. The Public Analyst Laboratory analyses a wide range of food products for contaminants and additives.
My work includes the development and transfer of methods for food analysis in our laboratory. I have worked in the area of food analysis for over thirty years using a wide range of analytical techniques P&T-GC/MS, GC, HPLC and IC.
More recently, I have been involved in the start-up and method development for the Analysis of Saturated, Unsaturated & Polyunsaturated fatty acids in foods. I have also worked in the development and validation for Nitrate Analysis in various foods using Ion Chromatography in our laboratories here in Cork.
Most recently, we validated and modified a method for the determination for Sulphur Dioxide in foods with Ion Chromatography .
