Determination of the concentration of ethanol in non-alcoholic beverages or in beverages with 0.0 % vol. alcohol using gas chromatography with headspace sampler and flame ionization detector (FID).
Can be used for all non-alcoholic drinks, drinks with 0.0 % vol. alcohol and beverages with > 1 % vol. after dilution.
The method is specific for ethanol and free of interference from other alcohols.
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.