A GAS CHROMATOGRAPHIC METHOD FOR THE ACCURATE DETERMINATION OF LOW CONCENTRATIONS OF VOLATILE SULPHUR COMPOUNDS IN ALCOHOLIC BEVERAGES

Abstract

By using a new sensitive method the contents of dimethyl sulphide, dimethyl disulphide and dimethyl trisulphide have been determined in beers and wines, and the contents of these sulphides and diethyl sulphite measured in distilled beverages. The head‐space volatiles are swept out from the beverage in a stream of nitrogen and adsorbed in a tube containing porous polymer. The volatiles are desorbed directly onto the column of a gas chromatograph by connecting the tube to the column and sliding the free end of the tube into the hot injection block from the oven side. The sulphur‐sensitive flame photometric detector is used and the peak areas and identifications are collected on cassette and processed by computer to give the content of volatile sulphur compounds directly in μg/litre beverage. The detection limits are 2 μg/litre for dimethyl sulphide, 0.1 μg/litre for dimethyl disulphide and trisulphide, and 5 μg/litre for diethyl sulphite. The analysis time for each sample is 30 min and the coefficient of variation is 5%. 1979 The Institute of Brewing & Distilling