The method is suitable for the determination of water vapor volatile aroma compounds in beer.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanolic distillate is saturated with NaCl. Potassium hydrogen sulfite is added to separate carbonyl groups that might interfere with the analysis. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging.
The method is suitable for beer brewed to any original gravity or to any alcohol content.
Volatile compounds in beer are concentrated through distillation and extracted with dichloromethane. The solvent phase is analyzed with a gas chromatograph. The linearity of the detector and the determination of the concentrations of analytes in the sample are achieved by using multiple concentration levels within the relevant range and through evaluation of the relative area under the peaks.
Determination of organic acids by means of reversed phase chromatography/ion chromatography
This method is suitable for wine, fruit juice and other non-alcoholic beverages.
The organic acids are separated using two combined columns, reversed-phase HPLC and an ion exchange column and are then determined using a UV detector.
Determination of the vicinal diketone content (diacetyl + 2,3-pentanedione) as well as the total diketone content in beer
The method is suitable for filtered beers brewed to any original wort or to any alcohol content as well as for fermenting wort.
Diacetyl (2,3-butanedione) and 2,3-pentanedione are detected photometrically in the beer after steam distillation. It is also possible to determine precursors in green beer.
Suitable for analysis of all (laboratory) wort samples
Atomic emission spectroscopy, also known as optical emission spectroscopy, in conjunction with inductively coupled plasma (ICP-AES or ICP-OES) is a technique used to determine and measure elements based on the phenomenon of atomic emission. The solutions to be analyzed are nebulized and the resulting aerosol is transported with the help of a carrier gas into an inductively coupled plasma (ICP). There, the elements are excited to a higher energy state, causing emissions. The spectrometer separates these emissions into individual wavelengths, and the intensities of the spectral lines of the element are measured with detectors (photomultipliers). A qualitative measurement is possible by calibrating the instrument with reference solutions, whereby a linear relationship exists over a broad range (generally several orders of magnitude) between the intensities of the emission lines (spectra) and the concentrations of the elements.
The method is suitable for the determination of steam-volatile aging indicators in beer.
Volatile aging indicator substances are driven out of the sample through steam distillation. The ethanol distillate is adjusted to be alkaline and saturated with NaCl. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging. The organic phase is further concentrated in a stream of nitrogen gas. Ammonia solution is added to remove the acids, as the acids would coelute, thus preventing the quantification of important substances.