M. Munar et al., QUANTITATION OF SULFUR-DIOXIDE RESIDUES IN MALT AND BEER BY HEADSPACEGAS-CHROMATOGRAPHY, Journal of the American Society of Brewing Chemists, 52(4), 1994, pp. 168-171
A method for the routine determination of both free and total sulfur d
ioxide (SO2) residues in malt and total SO2 in beer is described. The
basis of the method relies on the systematic formation of gaseous (SO2
) after acidification of the sample extract. A volume of the headspace
generated was analyzed by gas chromatography and the amounts of SO2 r
esidues were determined by comparing the peak height to a calibration
curve. Sodium sulfite was used as the external standard, and ethyl met
hyl sulfide was used as the internal standard.