The method is suitable for beers of all original gravities and of any alcohol content.
The gas chromatography headspace method is used to determine the higher alcohols and esters present in beer, i.e., the volatile compounds are transferred from the headspace in the sample vial into the GC system for analysis. The following substances are measured in this analysis:
Acetaldehyde
Propanol-1
Ethyl acetate
2-Methylpropanol
3-Methylbutanol
2-Methylbutanol
2-Methylpropylacetate
Butyric acid ethyl ester
3-Methylbutyl acetate
2-Methylbutyl acetate
Hexanoic acid ethyl ester
Determination of 3-hydroxy-2-butanone (acetoin) in beer.
The method is suitable for beers of brewed to any original gravity or of any alcohol content.
The compound 3-hydroxy-2-butanone (acetoin) is derived from diacetyl and is created through the reductive activity of yeast. One further reaction mechanism for the formation of 3-hydroxy-2-butanone is condensation of both free and activated (bound to thiamine pyrophosphate [TPP]) acetaldehyde.
3-Hydroxybutanone is oxidized to 2,3-butanedione (diacetyl) by iron chloride in the presence of iron sulfate and determined using gas chromatography and the headspace analysis method.
Determination of the total oxygen content (dissolved and in the headspace) in filled containers
The bottled or canned beer is brought to 20 °C and mechanically shaken, thereby achieving equilibrium between the oxygen dissolved in the beer and the oxygen present in the headspace (Henry’s and Dalton’s laws). By directly measuring either the oxygen in the beer or in the headspace, the total oxygen can be calculated through referencing a table of values, which includes the headspace volume as a percentage of the fill volume.
Drinking water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Vinyl chloride is determined using gas chromatography with detection by means of mass spectrometry (GC-MS) through application of the static headspace technique (HS). This method detects selected volatile organic compounds including chloroethene (vinyl chloride).
A known quantity of an internal standard (n-propanol) is added to the sample, if necessary after dilution.
The sample is equilibrated at a certain temperature in a headspace vial and part of the headspace is injected into a gas chromatograph.
The ethanol contained is separated on a polar gas chromatography column and detected with a flame ionization detector (FID).
The ethanol concentration in % vol. is calculated from the ratio of the area of the ethanol peak to the area of the internal standard (n-propanol) with the ratios of the same peaks determined when analyzing standards with known ethanol concentrations.
The method is suitable for beer brewed to any original gravity or to any alcohol content.
Higher alcohols and esters in beer are determined by gas chromatography using the headspace method, e.g., the volatile compounds are transferred from the gas space in the sample vial to the GC system for analysis. The method is suitable for beer brewed to any original gravity or to any alcohol content.