Title: Determination of free sulfite in wine by zone electrophoresis with isotachophoresis sample pretreatment on a column-coupling chip

Journal: Journal of Chromatography A Volume 1026, Issues 1-2 , 13 February 2004, Pages 31-39

INTRODUCTION

Sulfur dioxide and various oxoanions of S(IV) are widely used in food processing and preservation. Products formed by reactions of sulfite with natural food constituents and food preservatives are numerous (for details see, e.g., references [1, 2 and 3]). Of these, for example, adducts of hydrogensulfite anion with carbonyl groups of some food constituents are responsible for the fact that a part of the sulfur additive is present in food in a reversibly bound form [1]. The use of sulfiting agents in the vinification process is essential [4 and 5] and contents of sulfite in wines have close links with their use in this process. Adverse effects of the sulfiting agents are known [1, 2, 6 and 7] and an acceptable daily intake of sulfite advised [6]. Therefore, the determination of free and/or total sulfite is common in wine laboratories and these analytical tasks are included into a winery laboratory proficiency testing as well [8].