Determination of Aflatoxin B1 Contamination in Wheat and Rice Flour Collected from Iranian Market Using Simple and Reliable HPLC Method

Aflatoxin B1 (AFB1), as the most toxic mycotoxin, has a large variety of toxic effects to human and animals. To evaluate incidence of AFB1 in wheat flour and rice flour sold in Iranian markets, 40 samples including 16 wheat flour samples and 24 rice flour samples were collected from commercial brands commonly marketed in Iran and analyzed for their AFB1 content using post-column photochemical derivatization and HPLC. The mobile phase consisting of water, methanol and acetonitrile mixture (53:28:19, v/v/v). The sample preparation was done with simple extraction with acetonitrile and water (80/20, v/v) accompany with immunoaffinity column cleanup. Our results indicated a good recovery (minimal 90% in wheat flour and 97 % in rice flour) in spike range 0.2-8 µg.kg-1 with RSDs lower than 5%. The results showed both high incidence and high levels of AFB1 in rice flour samples compared to wheat flour. AFB1 was detected in 18.5% with maximum level of 0.26 µg.kg-1. AFB1 was found in 100% of rice samples with a mean and maximum level of 4.09±2.565 µg.kg-1 and 10.16 µg.kg-1, respectively. The results indicate that although the level of AFB1 in wheat flour is not comparatively critical point regarding quality of wheat flour, high incidence and high contamination level of AFB1 in rice flour samples could make serious health problems for Iranian consumers.