Quantitation of the homocysteine content in wine

Alcohol consumption has been previously shown to correlate with elevated plasma homocysteine levels, but investigations have not been carried out on the possible availability of this compound in alcoholic beverages such as wine or spirits. Therefore, in this study we investigated the levels of homocysteine in various Bulgarian wines. A total of 36 different Bulgarian wines with known origins were studied. The measured values were in the range of 0.09–0.64 mg l−1 for the tested white wines and in the range of 0.10–1.37 mg l−1 for the red wines. The method used for homocysteine determination was based on RP-HPLC with fluorescent detection after derivatization with N-(2-acridonyl)maleimide. The method was linear in the range of 0.0070–1.35 mg l−1 homocysteine and showed low limits of detection and quantification (LOD = 6 fmol, LOQ = 68 fmol). The within-run precision expressed as relative standard deviation (RSD, %) was 2.2–2.4% and the between-run precision was 2.6–3.9%. Enzyme immunoassay and LC-MS n analyses were used for confirmation of presence of homocysteine in wine.