Correlation between different clean-up methods and analytical techniques performances to detect Ochratoxin A in wine

Abstract

Three different clean-up methods and two analytical techniques were compared to determine Ochratoxin A (OTA) in wines. The first clean-up used a MycoSep column, the second an immunoaffinity column (IAC) and the third consisted in a liquid-liquid extraction (LLE) using dichloromethane in acid conditions. Meanwhile, two different OTA determination techniques were also evaluated: a HPLC analysis using a fluorescence detector and an enzyme-linked immunosorbent assays (ELISA) method. Correlations between clean-up methods and analytical techniques to determine OTA in wine were made evaluating linearity, accuracy and precision. Both the two first clean-up methods (solid-phase extraction, SPE) showed a good linear fit (r(2)=about 0.9999), followed by LLE. The use of immunoaffinity columns showed the best recoveries, even if also the SPE with MycoSep showed good recoveries while the LLE recoveries were the worst ones. The HPLC analysis showed good precision and accuracy, while ELISA method, even with a sufficient linearity, generally underestimated OTA content in wines.