Determination of ochratoxin A in wine from the southern region of Brazil by thin layer chromatography with a charge-coupled detector

The presence of ochratoxin A (OTA) is evaluated using thin layer chromatography (TLC) with a charge-coupled detector (CCD) in 88 red wine samples (2009 vintage) from Brazil. Samples included 75 wines from Rio Grande do Sul, nine from Santa Catarina and four from Parana state; 56 wines were Cabernet Sauvignon and 32 were Merlot varieties. The method included the analysis of fluorescent images, acquired under UV light, using ImageJ software. Mean recovery of OTA was 82.3% using immunoaffinity columns (IAC). The limits of quantification (LOQ) and detection (LOD) were 0.8 and 0.2 mg l(-1), respectively. Results showed a 5.7% contamination of OTA, with five positive samples -three Cabernet Sauvignon and two Merlot. Santa Catarina and Parana showed one positive sample each, although the concentrations were below the limit of quantification. The highest concentration found was 0.84 mg l(-1) in one sample from Rio Grande do Sul.