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 (plant wort) and beer.
The NDMA is extracted from the wort (plant wort) and beer on Extrelut®, Tox Elut® or comparable material using dichloromethane and the eluate is then concentrated. The determination is carried out by gas chromatography with the specific TEA detector ("Thermal Energy Analyzer"). Nitrosodipropylamine (NDPA) or nitrosodiisopropylamine (NDiPA) is used as the internal standard (ISTD). This detector detects nitrosamines according to the following scheme: After exiting the GC column, the separated substances first enter a pyrolysis oven, where they are heated to around 500 °C. The detector is used as an internal standard (ISTD). At this temperature, the (N-NO) bond of the nitrosamines breaks down, forming an NO radical (NO-):
The gas mixture then passes through a special filter (CTR Gas Stream Filter), which only allows the carrier gas and NO radicals to pass through. The NO radicals and ozone produced by a special generator then flow into a reaction chamber, where the following reaction takes place:
|
NO· + O3 |
→ |
NO2· + O2 |
| NO2· |
→ |
NO2 + h•ν |
These NO radicals react with ozone to form nitrogen dioxide in an excited state (NO2-) and oxygen. The NO2- decomposes spontaneously into ordinary nitrogen dioxide (NO2) by emitting radiant energy (h-ν) at a wavelength of around 600 nm.