analysis of aflatoxin b1 in iranian foods using hplc and a monolithic column and estimation of its dietary intake

a high performance liquid chromatographic method was developed for determination of aflatoxin b1 (afb1) in foods using a monolithic column with sample clean up on an immunoaffinity column. the method was validated for analysis of afb1 in rice, bread, puffed corn snack, wheat flour and peanut samples. the average recoveries for afb1 in different foods ranged from 94.4 to 102.5% with the coefficient of variation lower than 10% for all foods. limit of detection was 0.01 ng/g. a survey of afb1 was performed on 90 samples collected from tehran retail market in june 2005. the results showed that none of the bread and wheat flour samples were contaminated with afb1. the mean afb1 levels in rice, puffed corn snack and peanut samples were 4.17, 0.11, and 1.97 ng/g, respectively. the level of contamination of 3 samples (one rice sample and two peanuts samples) to afb1 was found to be higher than 5 ng/g. although all food samples had mean concentration of afb1 below the maximum tolerated level in iran, the mean intake of afb1 from rice was estimated 3.49 times higher than the guidance value of 1 ng afb1/kg body weight/day. therefore, it is strongly recommended to monitor afb1 in foods, especially in rice, in iran. this is the first study on exposure assessment of iranian population to afb1.