Quantitative Determination of Aflatoxin by High Performance Liquid Chromatography in Wheat Silos in Golestan Province, North of Iran

BACKGROUND Aflatoxins are the most common mycotoxins that contaminate crops. They are produced by fungi such as Aspergillus flavus and Aspergillus parasiticus. Wheat (Tricitumaestivum) is one of the most important staple foods used in Iran, and the environmental conditions in the north of Iran are favorable to fungal growth. This study was designed in order to determine the aflatoxin concentration in wheat samples from silos in Golestan Province north of Iran. METHODS Samples were collected from three silos of Golestan province. First, aflatoxins were isolated using immunoaffinity chromatography. Then the aflatoxin concentrations were determined by High performance liquid chromatography (HPLC) method and fluorescence detector. RESULTS Ten out of 34 samples (29.4% of samples) were contaminated by aflatoxins.No concentration was found above permitted aflatoxin levels in Iran (15 ng/g). In one sample (2.9%), aflatoxin B1 was seen over the permissible limits in Iran. The highest level found in samples for total aflatoxin, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 were 7.08 ng/g, 6.91 ng/g, 0.29 ng/g, 1.37 ng/g and 0.23 ng/g, respectively. No correlation was found between humidity levels in wheat samples contained aflatoxin and wheat samples without aflatoxin. CONCLUSION Despite the total aflatoxins determined in samples were below the permissible limits in Iran, the 29% aflatoxin contamination rate can negatively affect health factors and it should not be neglected. So, it is predictable that if the storage duration of samples increases, the aflatoxin contamination levels will increase.