Purpose: The purpose was to establish a sensitive and reliable analytical method for simultaneous determination of 13 mycotoxins in cereal grains by liquid chromatography-mass spectrometry (LC-MS/MS) and to monitor the levels of mycotoxins in samples collected from retail markets in South Korea by using the established analytical method.
Methods: We evaluated the linearity, sensitivity, specificity, and accuracy of the analytical method for determination of mycotoxins in cereal grains by LC-MS/MS after improved toxin extraction and purification using Myco6in1+ immunoaffinity columns. The method used to determine the levels of multi-mycotoxins in 500 cereal grains (100 each of brown rice, millet, sorghum, maize, and mixed cereal samples).
Results: The mycotoxin calibration curves had strong coefficient of determination (R2 > 0.99). The mycotoxin recovery rates were 100 – 119% (brown rice), 93.6 – 112% (millet), 88.2 – 102% (sorghum), 91 – 101% (maize), or 80.1 – 113% (mixed cereal) with % RSD of 0.57 – 7.89%, 0.25 – 9.17%, 0 – 1.97%, or 0.12 – 2.92%, 0.06 – 17.52%, respectively, at 8 – 326 ng/g of the spiked levels. The limits of quantification of the method for the mycotoxins were in the range of 0.6 - 6.0 µg/kg for all cereal grains. The incidence of the mycotoxins in samples collected from South Korean retail markets were 35%, 40%, 49%, 35%, and 34% in brown rice, millet, sorghum, maize, and mixed cereal, respectively.
Significance: The established method was suitable for assessing the incidence of multi-mycotoxins in cereal grains sampled from South Korean retail markets.