Measuring the Level of Main Mycotoxins in Wheat Samples Collected from Flour Factories Silos in Alborz and Tehran Provinces Using LC-MS/MS

Cereals and cereal-based products are prone to be infected by mycotoxin-producing fungi. The aim of this study was to investigate the level of contamination caused by 11 major mycotoxins in wheat samples collected from wheat silos in Tehran and Alborz provinces using UHPLC-MS/MS device.

Samples preparation was performed based on the extraction and purification procedures using acetonitrile/water/acetic acid solvents and Myco6in1 immunoaffinity columns, respectively. Selected mycotoxins were detected simultaneously using reversed phase ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) with electrospray ionization technique in positive-ion mode in a 15-minute run in the MRM program. Spiked samples calibration curve was used to overcome the matrix effects and to determine the residual mycotoxins.

Quantification and detection limits for AFB1 and OTA mycotoxins were 2 and 0.7 ppb; for DON, FB1, and FB2 were 100 and 33.3 ppb; for ZER were 50 and 16.6 ppb: for AFB2, AFG1, AFG2, and T-2 were 5 and 1.6 ppb; and for HT-2 were 20 and 6.6 ppb, respectively. Good precision and linearity was observed for mycotoxins. The average recovery rate of mycotoxins was in the range of 72-123 %, and the relative standard deviation (RSDr), indicating the method accuracy, was between 0.6-24.2 %. The validated method for analyzing the 30 wheat samples was used to evaluate the residual mycotoxins. OTA, T-2, and HT-2 mycotoxins were found in wheat samples. Only in one sample, the level of residual OTA exceeded the allowable limit set by the Iranian National Standards Organization.

The present study results highlighted the need for monitoring wheat and wheat-based products and the implementation of control and preventive measures in wheat fields, storage warehouses, and flour factories.