Liquid chromatography quadrupole time-of-flight mass spectrometry selective determination of ochratoxin A in wine

•Selective determination of ochratoxin A (OTA) in wine samples.•Quantitative extraction efficiencies with very low matrix effects.•Accurate quantification of spiked samples without need of matrix matched standards.•Unambiguous identification of OTA and OTC from their accurate MS/MS spectra.•Occurrence of OTA in dessert wines elaborated from dehydrated grapes. The performance of liquid chromatography quadrupole time-of-flight mass spectrometry (LC–QTOF-MS) for ochratoxin A (OTA) determination in wine is evaluated for the first time. Sample preparation was optimized to obtain quantitative recoveries at the same time that the efficiency of electrospray ionization (ESI) remained unaltered between sample extracts and calibration standards. Under final conditions, samples (20mL) were concentrated using a reversed-phase solid-phase extraction (SPE) cartridge, followed by OTA elution with 1mL of ethyl acetate. The absolute recoveries of the method, established against calibration standards, were 91–121% and 90–113% (without and with internal standard correction, respectively), for wines fortified at 3 concentration levels. The attained LOQ (0.05ngmL−1) remained below the maximum permitted OTA concentration (2ngmL−1) in dry wines. The method was applied to different samples, with OTA being found in some dessert wines at concentrations below 1ngmL−1. The ethyl ester of OTA (OTC) could be identified in the same wine samples from its accurate full product ion spectra.