Determination of amines and phenolic acids in wine with benzoyl chloride derivatization and liquid chromatography-mass spectrometry.

Amine and phenolic metabolites are important contributors to the flavor and health effects of many foods, including wine. Determination of these metabolites often involves UV detection following separation by liquid chromatography. While this is sufficient for some applications, chemical derivatization with LC-MS provides greater sensitivity and selectivity relative to LC-UV. We have developed an assay for 56 amine and phenolic metabolites in wine using benzoyl chloride derivatization and LC-MS. Isotopically labeled benzoyl chloride was used to prepare internal standards for each metabolite. Nanomolar limits of detection were achieved for all metabolites. To demonstrate the application of this assay, we compared metabolite profiles from Merlot and Cabernet Sauvignon wines from California and Australia. We found five metabolites which were significantly different when grouped by varietal, while twenty-four were different when grouped by location of production. This shows that the method can identify differences between various wines.