Progress in the Gas Chromatographic Determinations of Carbonyls and Other Volatiles in Beer. A. M. Jamieson and G. Van Gheluwe, Molson Breweries of Canada Limited, Montreal, Quebec, Canada H2L 2R5. J. Am. Soc. Brew. Chem. 35:0073, 1977.

This paper is the fifth in a series covering the formation, isolation, and identification of 2-nonenal and is mainly concerned with reporting some of the difficulties encountered in developing a quantitative method of analysis for carbonyls in beer. Included in the paper are observations on direct injection, purging, sample and solvent purification, artifact formation and aldehyde instability. The results from these observations are incorporated in a refined procedure which offers simplification of the apparatus, the use of a more suitable internal standard (2-octanone), and improvements in the method of recovery. Several compounds have been identified by gas chromatography/mass spectrometry, including two which are peculiar to a physically and organoleptically unstable beer.

Keywords: 2-Butanone, Carbonyls, Gas chromatography, 4-Methyl-2-pentanone, Volatiles.