Quantitation of ochratoxin a in cereals and feedstuff using sequential injection analysis with luminescence detection E.J. Llorent-Martínez, P. Ortega-Barrales, M.L. Fernández-de Córdova, A. Ruiz-Medina * Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas, E-23071 Jaén, Spain article info Article history: Received 27 March 2012 Received in revised form 18 July 2012 Accepted 24 July 2012 Keywords: Mycotoxin Automation SIA Maize Sorghum SPS abstract Ochratoxin A is one of the most important mycotoxins due to its global incidence and toxicity. Therefore, many countries have adopted regulations or guidelines to limit exposure and protect human and animal health. In this paper, we have developed two different flow-through optosensors using sequential injection analysis, and compared them in terms of analytical parameters. One of them used fluorescence detection, whereas the other one used terbium-sensitized luminescence detection. In both cases, an appropriate solid support was placed inside the flow-cell to retain the analyte and increase the selectivity and sensitivity of the system. The extraction of ochratoxin A from cereals and animal feedstuff was performed with a modified QuEChERS method. The obtained detection limit made it possible to fulfill the Commission of the European Communities Recommendation guidance values for this contaminant in feed. Recovery experiments were carried out in cereals and several feed samples at different fortification levels. Recoveries in the 86e112% range were obtained, therefore demonstrating the applicability of the proposed analytical method for quality control analyses. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction There is a growing concern regarding mycotoxin contamination in food and feed, as they can be found in a wide range of commodities, including cereals, spices, dried fruits, apple products, wine and coffee. The Food and Agricultural Organization (FAO) of the United Nations has estimated that up to 25% of the world’s food crops are significantly contaminated with metabolites of toxigenic molds: mycotoxins (Duarte, Lino, & Pena, 2010). Of these, ochra- toxin A (OTA), which is produced by several fungal species of the genera Penicillium and Aspergillus, is one of the most important ones due to its global incidence and toxicity. Studies have shown that this molecule can have several toxicological effects, such as nephrotoxic, hepatotoxic, neurotoxic, teratogenic and immunotoxic (El Khoury & Atoui, 2010). In fact, OTA is classified as a possible human carcinogen (group 2B) by the International Agency of Research on Cancer (IARC) (IARC, 1993). Although OTA primarily affects the kidneys in animals exposed to naturally occurring levels (Pavón, González, de la Cruz, Martín, & Lacarra, 2012), it can also produce other damages such as liver tumors (El Khoury & Atoui, 2010) or affecting the immune system (Matrella, Monaci, Milillo, Palmisano, & Tantillo, 2006). However, the impact of OTA upon animals extends beyond health effects. The economic impact of lowered productivity, reduced weight gain, reduced feed efficiency, and greater disease incidence because of immune system suppression must be taken into account. Finally, it is important to mention the recognized potential of the carry-over effect, from the consumption of contaminated animal products by humans. OTA presents high stability as well as resistance to acidity and high temperatures. Thus, once food- and feedstuff are contami- nated, it is very difficult to totally remove this molecule. In addition, the high affinity of OTA to proteins, particularly to serum albumin, allows its accumulation in the organs of animals (Hagelberg, Hult, & Fuchs, 1989). In fact, animal-derived products and tissues intended for human consumption may present OTA residues even if the animal has been nourished with feed contaminated with low levels of OTA (Miliceví, Juric, Stefanovic, Jovanovic, & Jankovic, 2008). As a result, the European Union (EU) and different countries world- wide have established regulations for food and feed (CEC, 2006, 2012; Duarte et al., 2010). Therefore, it is important to develop reliable analytical methods for OTA determination not only in products intended for human consumption, but also in feedstuff. In the last years, most of the methods developed for OTA determination are based in liquid chromatography with mass spectrometry (Liao, Lin, Chiueh, & Shih, 2011; Soleimany, Jinap, & * Corresponding author. Tel.: þ34 953 212759; fax: þ34 953 212940. E-mail address: anruiz@ujaen.es (A. Ruiz-Medina). Contents lists available at SciVerse ScienceDirect Food Control journal homepage: www.elsevier.com/locate/foodcont 0956-7135/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodcont.2012.07.036 Food Control 30 (2013) 379e385