Fast and Selective Determination of Ochratoxin A in Wines Using an Optimized and Validated Liquid Chromatographic Method

Determination of ochratoxin A (OTA) in wines requires a cleanup step using solid phase extraction (SPE). Immunoaffinity columns are commonly the columns of choice but due to its high cost, other SPE columns have been assayed without optimal results. The present work reports an optimized and validated liquid chromatographic method for a fast and selective quantification of OTA in wines using C-18 columns for cleanup. Chromatographic conditions were optimized using a central composite design, establishing the following optimal conditions: acetonitrile/water/acetic acid (59.5:39.5:1.0 v/v/v) as mobile phase, flow rate of 1.2 mL min(-1), and column temperature of 30 A degrees C. With these conditions, OTA had a retention time (similar to 4 min) up to five times lower than those reported earlier. Regarding validation, calibration data (n = 8) fitted a linear regression model with a determination coefficient (R (2)) of 0.9992. Repeatability (relative standard deviation (RSD)) and intermediate precision (RSD) in matrix showed values of 1.3 % (n = 6) and 0.8 % (n = 3), respectively. Recoveries at five levels ranged from 87.2 to 118.9 % (mean RSD of 7.4 %). Fifty-three samples from different origins were analyzed, finding only seven samples (13 %) with quantifiable OTA content (0.15-0.26 mu g L-1). According to the levels found, the contribution of wine consumption to OTA daily intake was at least 58 times lower than the current tolerable daily intake. In view of optimization and validation results as well as its applicability to real samples, this method could be considered a good alternative for routine analysis of OTA in wines.