Abstract 026
A New Calibration Procedure for the Determination of Dimethyl-sulfide in Beer Using Gas Chromatography with a Flame-Photometric Detector
J. Amer. Soc. Brew. Chem. 44: 57-66, 1986
S.S. Lee and K.J. Siebert
Procedures used to calibrate the flame photometric detector for detn. of dimethyl sulphide (DMS) in beer headspace by GC were investigated. substantial differences in results were attributed to differential quenching responses to DMS and the internal standard, caused by nonsulphur-containing compounds eluting at the same times, and to the use of inappropriate calibration methods. A calibration procedure using beer as the medium and iteration techniques at high levels of added DMS was developed. Its applicability was verified with several different beers. Results obtained with this procedure differed from those obtained by the commonly used square root method by as much as 36-206%. The results indicated that a calibration curve constructed for one beer cannot be applied to others. A simplified procedure for obtaining a correction factor for preparing calibration curves in different beers is proposed. The DMS concn. and correction factors determined for 6 different beers ranged from 16 to 45 µg/l and from 0.37 to 1.77, resp. Calibration described should also have application in the detn. of other S compounds with the flame photometric detector.
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