Rapid determination of volatiles in alcoholic beverages by precolumn-backflush gas chromatography

✍ Scribed by Hagman, Gunnar ;Roeraade, Johan

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 331 KB
• Volume: 13
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240130205

✦ Synopsis

Abstract

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.