Method for determining the ethanol content of alcoholic beverages

Abstract

Abstract The volumetric ethanol content of a liquid mixture containing water and ethanol (e.g., an alcoholic beverage) is determined by gas-solid chromatography using aqueous ethanol of known composition as an external calibration standard. A pre-determined volume of sample mixture to be analyzed is injected into a gas chromatographic column containing a solid hydrophobic microporous adsorbent and chromatographed. The adsorbent is a non-polar organic copolymer derived from divinyl benzene as a cross-linking agent and a hydrocarbon monomer possessing a polymerizable CH CH2 substituent (e.g., styrene, ethylvinyl benzene). An external calibration standard prepared by mixing a known volume of water with a known volume of ethanol is likewise separately chromatographed. The components of each injected sample are separated as they travel through the column and then detected by a thermal conductivity detector, thereby generating signals which are amplified and converted to digital form. The digital values corresponding to the amplified detector signals are transmitted to an integrator. Concurrently, analog signals can be transmitted to a chart recorder which registers the signals on a chromatogram as a series of peaks corresponding to the water and ethanol components of the sample mixture and external standard. The integrator provides a report of the numerical areas under the peaks, which is subjected to mathematical treatment to arrive at the volumetric content of ethanol in the sample mixture.

Inventors

• 👤 Donald E Goodman

Bibliographic Details