VIEW ARTICLE DOI: 10.1094/ASBCJ-50-0001
Determination of Sulfite in Beer Using Ion-Exclusion Chromatography and Pulsed Amperometric Detection. Herbert P. Wagner and Michael J. McGarrity, Brewing Research Department, John Labatt Ltd., London, Ontario, Canada N6A 4M3. J. Am. Soc. Brew. Chem. 50:0001, 1992.
The use of ion-exclusion chromatography combined with electrochemical detection has been suggested for the analysis of total SO2 in beer. However, direct amperometry is prone to errors resulting from the loss of detector sensitivity, which occurs as the working electrode becomes contaminated. The sequential analysis of calibration standards and samples is required to overcome these difficulties. Pulsed amperometry was investigated as a means of maintaining electrode integrity and detector sensitivity and thereby eliminating the need for the sequential analysis of standards and samples. Correlation coefficients of 0.997 or better were obtained in both pH 9 buffer and beer. Excellent spike recoveries of SO2 added to beer were obtained. The small coefficient of variation and good agreement with the standard para-rosaniline method indicates that this ion-chromatographic method is both precise and accurate.