Validation study of immunochemical elisa assay for ochratoxin a quantification in dessert wines from sun-dried grapes

ochratoxin a (ota) contents have implications on consumers safety and wine quality. immunological methods are widely used to determine ota in various matrices. solid-phase extraction with immunoaffinity columns containing antibodies specific to ochratoxin a were used to clean-up the samples by two different methods in alkaline medium. competitive enzyme-linked immunosorbent assay (elisa) commercial kit was utilized for ota quantification in dessert wines samples. this elisa assay uses an instrumental response based on absorbance measurements at 450 nm. the method was performed with standard solutions (provided with the kit), in spiked and naturally contaminated wine samples. the detection limit was 0.054 ìg/l and recoveries of ota from spiked wine samples, at levels from 1 to 3 ìg/l, ranged from 94 to 102%, with relative standard deviations less than 3%. this elisa method was checked against an official instrumental method like hplc with tandem mass spectrometric and with fluorescence detection. elisa kit method resulted effective for measuring ota ranging from 0.25 to 9 ìg/l in dessert wines.