Boutsiadou-Theurillat X.,Laboratory of Food Contaminants |
Meier P.,Laboratory of Food Contaminants |
Richard C.,Laboratory of Food Contaminants
Chimia | Year: 2014
The aim of this study is a current trend in chemical food safety control to increase monitoring of the co-occurrence of mycotoxins. Unsanitary conditions during harvesting, drying, packing and storage in production and processing of cereals can effect mycotoxin contamination. A method was developed for the simultaneous determination of 11 mycotoxins: deoxynivalenol, aflatoxins B1, B2, G1 and G2, ochratoxin A, fumonisins B1 and B2, zearalenone, and toxins T-2 and HT-2, allowing confirmation of their presence in maize samples as well as their identification and semi-quantification. The mycotoxins are extracted with a mixture of methanol/water, diluted with water and 0.1% formic acid and then analyzed by LC-HESI-MS/MS in a single 12 min run in positive mode. Multiple reaction monitoring mode (MRM) is applied by using two abundant fragments for each mycotoxin. Matrix effects are compensated using external matrix-matched calibration curves. Recoveries, calculated by spiking blank maize samples, ranging from 95.2% to 113.4%, were in accordance with the performance criteria required by the European Commission and intraday reproducibility ranged from 4.2% to 13.2%. Proficiency test materials and reference materials were analyzed to assess the accuracy of the method with satisfying results for the 11 mycotoxins. The method was used for monitoring of maize samples on sale in Switzerland. © Schweizerische Chemische Gesellschaft.
Vareli K.,University of Ioannina |
Touka A.,University of Ioannina |
Theurillat X.,Laboratory of Food Contaminants |
Briasoulis E.,University of Ioannina |
And 2 more authors.
Clean - Soil, Air, Water | Year: 2015
The eutrophic character of a growing number of freshwaters around the world is a global health concern as in these high nutrient ecosystems toxic cyanobacteria often bloom. The well-studied cyanobacterial toxins are microcystins (MCs), a family of more than 90 closely related hepatotoxic heptapeptides. Since MCs are products of the first trophic level, they tend to accumulate in the food chain. Moreover, there is evidence suggesting that irrigation with contaminated water results in severely contaminated crops. As expected, scientific efforts have focused on the elucidation of mechanisms for cyanobacterial bloom formation and toxicity in these eutrophic freshwaters. However, recent studies indicated that oligotrophic freshwaters are also prone to toxic cyanobacterial blooms. In this context, we compared the toxic potential of two low nutrient lakes in NW Greece to a eutrophic lake of the same region. Interestingly, in seston samples, MC concentrations were found to be higher in these lakes. Cyanobacterial communities were compared based on molecular data. Our findings suggest that the MC producers are mainly cosmopolitan non-diazotrophic cyanobacteria. In conclusion, based on the results, monitoring programs should be established for oligotrophic lakes to prevent of health hazards from use of such "innocent" ecosystems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.