engleski

HPLC method for zearalenone determination in wheat

Zearalenone (ZEA) is natural product of some Fusarium moulds that grow on cereals in mild and tropical climatic zones. ZEA has very low acute toxicity, but the ZEA contamination may present a serious health problem due to its estrogenic activity in animals and humans. For some time in the past it was used as in the treatment of dismenorhoic disturbances. There is no data on its carcinogenicity in humans because of the lack of epidemiological studies. In our country data on the ZEA contamination of wheat are rather scarce. The only data, which can be found in open literature, are obtained by use of TLC methods, which are relatively insensitive. Therefore we have decided to introduce a sensitive and reliable HPLC method and to test it on the wheat infected artificially in the field with Fusarium moulds. Wheat was artificially infected in field with Fusarium moulds and harvested in Summer 2002. Samples (N=55) were collected and stored at -80 0C until analyzed. ZEA was extracted from wheat samples as described by Llorens A. et al. (Food Addit Contam 2002 ; 19, 272-281) and samples were cleaned-up using Bond Elut C-18 columns (Varian, Harbor City, CA, USA). The concentration of ZEA was determined using HPLC with fluorescent detector. Mobile phase consisted of methanol and water (80+20), and the flow rate was 0.5 ml/min. The separation of ZEN was performed on C-18 reverse phase analytical column (LiCroCART, Merck, Darmstadt, Germany) 250x4 mm, 5 mm particle size. For fluorescence detection wavelengths were set at lex 274 nm and lem440 nm. Calibration curve, calculated from standards prepared in methanol was linear (r2=0.9992). Reproducibility of the method (precision form day to day) calculated as relative standard deviation (RSD) was 5.6%. Detection limit of the method was 0.39 mg/kg and recovery was 108%. ZEA was found in all 55 samples of wheat artificially infected in field with Fusarium moulds. The concentration range was from 0.67 to 10.98 mg/kg and mean concentration was 3.47 mg/kg. These results indicate that the introduced HPLC method for ZEA determination in wheat may be used for naturally contaminated samples.

zearalenone; mycotoxins; liquid chromatography; wheat

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