DIN EN 15835:2010-05

Mycotoxins are very harmful secondary metabolites produced by mold. Foodstuffs which are grown, harvested or stored under wet conditions can be attacked by mold the metabolites of which will then enter the food. Toxicity of some mycotoxins is significant for human beings; therefore a solid proof is particularly important for the health protection of consumers. In Germany Ordinance on the maximum permissible quantities of mycotoxins in foodstuffs has been introduced in order to reduce mycotoxin contamination. Since 2004 it contains not only regulations for aflatoxins, but also for ochratoxin A, fumonisins, deoxynivalenol and zearalenone. Since 2001 national provisions have been supplemented by regulations on the maximum content for contaminants in foodstuffs which are applicable throughout the EU. Maximum contents of mycotoxins in certain foodstuffs are also regulated by various other regulations. Therefore a uniform Europe-wide method for the determination of mycotoxins is essential in order to assure the health protection of consumers. This European standard on the determination of ochratoxin A in cereal based foods for infants and young children has been prepared by Technical Committee CEN/TC 275 "Food analysis - Horizontal methods" (secretariat: DIN, Germany) of the European Committee for Standardization (CEN) after in-depth preliminary work of Working Group 5 "Biotoxine" ("Biotoxins"). The responsible German committee is Working Committee NA 057-01-03 AA "Biotoxine" ("Biotoxins") of Food and Agricultural Products Standards Committee (NAL) of DIN, the German Institute for Standardization. This standard specifies a method for the determination of ochratoxin A in cereal based foods for infants and young children by high performance liquid chromatography (HPLC) with immunoaffinity column cleanup and fluorescence detection. This method has been validated in a collaborative study via the analysis of both naturally contaminated and spiked samples with contents ranging from 0,050 µg to 0,217 µg/kg. In further investigations the method has been shown to be applicable to baby foods containing 8 different types of cereals, honey and cocoa, at levels up to 3,540 µg/kg. The test portion of the sample is extracted with tert-butyl methyl ether after addition of a mixture of 0,5 mol/l phosphoric acid and 2 mol/l sodium chloride solution. The extract is evaporated and redissolved in a mixture of methanol and phosphate buffered saline (PBS) solution. After removal of lypophilic compounds with hexane, the extract is applied to an immunoaffinity column containing antibodies specific to ochratoxin A. The toxin is eluted from the column with methanol. Ochratoxin A is determined by HPLC with enhanced fluorescence detection involving post-column reaction with ammonia.