A multi-analyte LC-MS/MS method for the analysis of 23 mycotoxins in different sorghum varieties: the forgotten sample matrix

An LC-MS/MS method was developed and validated for the detection and quantification of 23 mycotoxins in different varieties of sorghum. The method performance characteristics were as follows: suitable linearity ranges for all 23 mycotoxins with p-value >0.05; limits of detection (1.2-50 μg/kg), limits of quantification (2.5-100 μg/kg), repeatability (RSDr, 7-22%), intermediate precision (RSDR, 14-44%) and apparent recovery (0.2-11%, expressed as bias). The method was applied to analyze 10 samples obtained from retail shops in Belgium (n=8) and Germany (n=2). Nine of the 10 samples (90%) were positive for the following mycotoxins: aflatoxin B1 (50 μg/kg), alternariol monomethyl ether (<LOQ - 79 μg/kg), alternariol (303-357 μg/kg), diacetoxyscirpenol (<LOQ - 91 μg/kg), fumonisin B1 (<LOQ - 95 μg/kg), fumonisin B2 (<LOQ), fumonisin B3 (<LOQ), T2 (<LOQ) and zearalenone (<LOQ).