Fumonisins B^sup 1^ and B^sup 2^ in Agricultural Products Consumed in South Korea: An Exposure Assessment

To survey fumonisins B^sub 1^ (FB^sub 1^) and B^sub 2^ (FB^sub 2^) in agricultural products consumed in South Korea and provide an exposure assessment, ground samples were extracted (80% MeOH), filtered (0.2 µp?), and cleaned up. After evaporation, dry residues were reconstituted in 50% MeOH, and a 50-µ1 aliquot of this sample was mixed with 200 µl of o-phthaldialdehyde for derivatization. The derivatives were analyzed with a high-performance liquid chromatography system equipped with a fluorescence detector. For validation of the detection procedure, linearity, accuracy, precision, detection limit, and quantification limit were determined. The validated detection method was then used to survey fumonisins in white rice, brown rice, barley, barley tea, beer, wheat flour, millet, dried corn, corn flour, corn tea, canned corn, popcorn, and breakfast cereal. Retention times for FB^sub 1^ and FB^sub 2^ standards were 7 and 18 min, respectively. Linearity (R^sup 2^ = 0.99995 to 0.99998), accuracy (81.47 to 108.83%), precision (2.35 to 5.77), detection limit (25 ng/g or ng/ml), and quantification limit (37 ng/g or ng/ml) indicated that this procedure is capable of quantifying fumonisins in agricultural products. Only FB^sub 1^-positive samples (5.12%, three dried corn samples and five corn flour samples) were found at 90.89 to 439.67 ng/g. According the survey results, an estimated daily intake of FB^sub 1^ and FB^sub 2^ in Korea was 0.087 ng/kg of body weight per day. These results indicate that continuous monitoring of these mycotoxins is necessary to establish appropriate risk assessment, and the maximum tolerable daily intake of fumonisins in Korea is lower than the 2 µg/kg set by the Joint Food and Agriculture Organization-World Health Organization Expert Committee. [PUBLICATION ABSTRACT]