Method for determining nitrogenous heterocycle compounds in wine.

Qualitative and quantitative analyses of N-heterocycle compounds were conducted by using a liquid-liquid extraction followed by additional chemical silica gel purification and injection into a gas chromatographic (GC) column coupled to a nitrogen-phosphorus detector (NPD). The purified extract fraction was investigated by GC-NPD and by GC-mass spectrometry. The compounds identified and quantified in wines were 2,4,5-trimethyloxazole, 2,4-dimethylthiazole, and 4-methylthiazole by GC-NPD and both 2-acetylthiazole and 2-acetyl-2-thiazoline by GC-MS. The procedure was used to analyze different wines and gave reliable and reproducible results.