ORIGINAL PAPER Fluorescence polarization immunoassay for rapid screening of ochratoxin A in red wine Francesco Zezza & Francesco Longobardi & Michelangelo Pascale & Sergei A. Eremin & Angelo Visconti Received: 4 June 2009 / Revised: 16 July 2009 / Accepted: 17 July 2009 / Published online: 8 August 2009 # Springer-Verlag 2009 Abstract A fluorescence polarization (FP) immunoassay, based on a monoclonal antibody and an ochratoxin A (OTA)-fluorescein tracer, has been developed for rapid screening of OTA in red wine. Wine samples were diluted with methanol and passed through aminopropyl solid-phase extraction columns prior to the FP assay. Average recover- ies from samples spiked with OTA at levels of 2.0 and 5.0 ng/mL were 79% with RDS of 11% (n =6). The limit of detection of the FP immunoassay was 0.7 ng/mL OTA, and the whole analysis was performed in less than 10 min. The assay was tested on 154 red wine samples (naturally contaminated or spiked at level ranging from 0.1 to 5.0 ng/mL) and compared with an high-performance liquid chromatography/immunoaffinity column clean-up method, showing a good correlation (r =0.9222). Their compliance with the European regulation (2.0 ng/mL OTA maximum permitted level) was correctly assessed for 70% of the analyzed samples of red wine, whereas confirmatory analyses were required for the remaining ones with OTA levels close to the regulatory limit. No false-negative or positive results were observed using the FP immunoassay. The proposed FP assay is a useful screening method for OTA in red wines, when high throughput is required, that could also be used for white and rosé wines, which are known to contain less interfering compounds such as polyphenols. Keywords Ochratoxin A . Fluorescence polarization immunoassay . Solid-phase extraction . Wine . Rapid methods Introduction Ochratoxin A (OTA) is a mycotoxin produced by several fungal species, mainly belonging to Aspergillus and Penicillium genera, that can contaminate several foods and beverages, including cereals, beans, nuts, spices, dried fruits, coffee, cocoa, beer, and wine. OTA is a potent nephrotoxic agent and has been shown to be hepatotoxic, genotoxic, cytotoxic, teratogenic, and immunotoxic to different animal species. It has been shown to cause cancer in rats and mice and suspected to be involved in the pathogenesis of the Balkan Endemic Nephropathy and tumors of the upper urinary tract in humans [1, 2]. The International Agency for Research on Cancer has classified OTA as a possible carcinogen to humans (group 2B) [3]. Based on the results of the EU SCOOP project, Scientific Cooperation Task 3.2.7, wine is the second major source of OTA dietary intake by the EU population, following cereals [4]. Several surveys have shown high incidence and high levels of OTA contamination in red wines, mainly from Southern Europe as compared to other regions, and a decrease of toxin contamination levels from red to rosé to F. Zezza : F. Longobardi : M. Pascale (*) : A. Visconti Institute of Sciences of Food Production, National Research Council, Via G. Amendola 122/O, 70126 Bari, Italy e-mail: michelangelo.pascale@ispa.cnr.it S. A. Eremin Division of Chemical Enzymology, Faculty of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia Present Address: F. Longobardi Department of Chemistry, University of Bari, Via Orabona 4, 70125 Bari, Italy Anal Bioanal Chem (2009) 395:1317–1323 DOI 10.1007/s00216-009-2994-3