Occurrence and simultaneous determination of nivalenol and deoxynivalenol in rice and bran by HPLC-UV detection and immunoaffinity cleanup

A simple and accurate method for simultaneously quantifying two co-occurring Fusarium mycotoxins in rice and bran, nivalenol (NIV) and deoxynivalenol (DON), is described. The method involves the use of an immunoaffinity column for cleanup and HPLC-UV detection for quantification. The limits of quantification were <11.09 μg kg−1 for the two toxins in rice and bran. The mean recoveries from blank samples spiked at levels of 100-1000 μg kg−1 were 86.2-106.6% for NIV and 93.1-106.2% for DON, with relative standard deviations of 6-15% for NIV and 3-11% for DON, respectively. The detection rate of NIV in 482 rice and 239 bran samples was 34-96%, where the level ranging from 5.7 to 2791.4 μg kg−1, whereas that for DON was 10.4-44.8% with levels ranging from 7.1 to 655.6 μg kg−1. The co-occurrence rates of NIV and DON were 9.1%, 14.9%, and 41.5% for white rice, brown rice, and bran, respectively. The estimated dietary intakes of NIV and DON for the Korean population based on the occurrence data were well below the established tolerable daily intake.