A Semi-Automatic Method for the Gas Chromatographic Determination of Vicinal Diketones in Alcoholic Beverages

Abstract

A method has been developed for the routine determination of diacetyl and pentanedione in alpoholic beverages. After the addition of internal standard and any necessary dilution, a stream of nitrogen swept the components of the sample at a fixed temperature to a 2 ml injection loop of a gas chromatograph fitted with an electron capture detector. The data from the chromatograph were collected on cassette and processed by computer. The time between starting tempera ture equilibration of the sample and obtaining the diketone content as /ig/litre beverage was about 17 min. The coefficient of variation for diacetyl was 1 -8% (5-1%, with manual injections) and for 2,3 pentanedione 1 6% (91%) for replicated analyses of the same sample.

The detection of ?-dicarbonyl compounds in wine by formation of quinoxaline derivatives

“…It is derived from previous studies using diaminobenzene for the determination of diacetyl and related products. 17,18 MATERIALS AND METHODS Reagents Dicarbonyl compounds were purchased from Aldrich Chemicals and used without further puri®cation: glyoxal (12,, methylglyoxal (17,, phenylglyoxal (14,243-3) diacetyl (B8,530-7), pentane-2,3-dione (24,196-2) and hexane-2,3-dione (14,. 1,2-Diaminobenzene (Sigma, o-phenylenediamine P-9029) was used directly in powder form or as an aqueous solution.…”

Wine aroma composition: identification of additional volatile constituents of red wine

“…The ethoxy and acetyloxy compounds may result from fermentation byproducts through secondary reactions, e.g., the hydroxy ketones acetoin and 3-hydroxy-2-pentanone occurring in relatively high concentrations in red wines along with the corresponding vicinal diketones (Kavadze et al, 1977; Leppánen et al, 1979) may be considered as precursors for the ethoxy ketones identified in this study.…”