Determination of the amine content in wort and beer
This method is suitable for wort and beer.
Determination by means of reversed phase chromatography after pre-column derivatization with dansyl chloride and fluorescence and UV detection.
Determination of the nitrosamine content in wort and beer.
This method is suitable for wort and beer.
NDMA present in wort and beer is extracted on Extralut® or a comparable material using dichloromethane, followed by concentration of the eluate. The determination is performed with a gas chromatograph with a specific TEA detector (thermal energy analyzer); nitrosodipropylamine (NDPA) or nitrosodiisopropylamine (NDiPA) serves as an internal standard (ISTD). This detector analyzes nitrosamine according to the following procedure: After exiting the GC column, the separated substances are heated to approximately 500 °C in a pyrolyzer. At this temperature, the (N-NO) bond of the nitrosamine is broken, thus forming an NO radical (NO·):
The NO radicals then flow into a reaction chamber along with ozone, which is created by a special generator designed for this purpose. The following chemical reactions take place in the chamber:
|
NO· + O3 |
→ |
NO2· + O2 |
| NO2· |
→ |
NO2 + h•ν |
These NO radicals react with ozone, forming nitrogen dioxide in an excited state (NO·2). The NO·2 molecules decompose spontaneously to form nitrogen dioxide in its common form (NO2), emitting radiation (h•ν) at a wavelength of approx. 600 nm.