Comparison of different immunoaffinity clean-up procedures for high-performance liquid chromatographic analysis of ochratoxin A in wines

Three immunoaffinity clean-up procedures to analyse ochratoxin A (OTA) in w ines were compared. The direct wine clean-up with Ochraprep and OchraTest c olumns gave equivalent results in terms of recovery and precision if compar ed with the reference procedure involving a preliminary extraction of OTA w ith chloroform. OTA quantification limit in wine ranged from 0.020 to 0.045 mu g/l. The 'on-flow' OTA emission spectrum (excitation 333 nm) showed a m aximum at 460 nm and could be used to confirm the quantitative results. The analysis of 11 red and white wines gave no significant quantitative differ ences between the three clean-up techniques. (C) 2000 Elsevier Science B.V. All rights reserved.