Determination of Total Sulphur Dioxide in Beer Samples by Flow-Through Chronopotentiometry
Josef Dvorák1, Pavel Dostálek1,4, Karel Šterba1, Pavel Cejka2, Vladimír Kellner2, Jirí Culík2 and Ernest Beinrohr3
1 Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
2 Research Institute of Malting and Brewing, Plc., Lípová 5, 120 44 Prague 2, Czech Republic.
3 Department of Analytical Chemistry, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovak Republic.
4 Corresponding author. Email: Pavel.Dostalek@vscht.cz
J. Inst. Brew. 112(4), 308–313, 2006 | VIEW ARTICLE
ABSTRACT
A chronopotentiometric method for the determination of total sulphur dioxide in beer is described. Free and bound sulphites were converted to sulphite anions on alkalising the sample solutions. On acidifying the solution, the released sulphur dioxide was on-line separated through a semipermeable membrane and transported by an electrolyte into the measuring cell and measured by stripping chronopotentiometry. The proposed method was validated and compared with the three EBC methods. The RSD of repeatability was 8.6% for the normal SO2 level in the beer (3.4 mg/L). The results corresponded well with those obtained with the alternative EBC methods. The elaborated method was much faster and simpler than the EBC methods.
Key words:
Beer, sulphur dioxide, electrochemical analysis, flow-through stripping chronopotentiometry.
Publication no. G-2006-1305-439 ©2006 The Institute & Guild of Brewing