ISSN:
0935-6304
Keywords:
Gas chromatography, GC
;
Precolumn-backflush
;
Alcoholic beverages
;
Selectivity change caused by water
;
Direct analysis
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A method for quantitative determination of volatiles such as ethyl acetate, acetaldehyde, and methanol in alcoholic beverages is described. A short packed precolumn coupled to a capillary column via an effluent splitter is employed. The less volatile part of the sample is retained on the precolumn and back-flushed using a 10-port rotary valve, while the volatiles areseparated on the capillary column. The advantage of the system is that the analysis time per sample can be reduced to a few minutes. Moreover, the capillary column can be kept at low temperature, since it is not contaminated with material of low volatility.The water in the sample was found to have a significant influence on the retention of the compounds (as also observed earlier by Grob und Habich [1] ). This effect was exploited to increase the resolution between ethyl acetate and methanol, by injecting a portion of pure water prior to sample injection. Apart from the better separation, the water vapor also has a deactivating effect.The packed precolumn tolerates large amounts of non-volatile material. Even after several hundred direct injections of wine and spirits, the chromatographic performance of the system was still satisfactory.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jhrc.1240130205
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