Determination of 3-Methyl-2-Butene-1-Thiol in Beer. Henry Goldstein, Sydney Rader, and Aki A. Murakami, Miller Brewing Company, Research Department, Milwaukee, WI 53208. J. Am. Soc. Brew. Chem. 51:0070, 1993.

Three-methyl-2-butene-1-thiol, the compound responsible for the light-struck character in beer, was determined at levels below 1 ng/L in beer. The sensory threshold in American lagers is 1-5 ng/L. Beer was first gas extracted, thiols were trapped on an Hg (II) cyanide trap, and thiols were freed from the trap with acid and extracted into dichloromethane. An aliquot of the dichloromethane thiol solution then was injected (on-column injection) into a gas chromatograph. Detection was by flame ionization, flame photometry, mass spectrometry, or sulfur chemiluminescence detectors.

Keywords: Light-struck, 3-Methyl-2-butene-1-thiol, Mercaptan, Thiol