Analytical Methods of Multi-mycotoxins for Total Diet Study

Abstract

Mycotoxins are naturally occurring secondary metabolites produced by fungi species of Aspergillus, Fusarium, and Penicillium, and potentially having carcinogenic toxicities. In this study, analytical methods of aflatoxins, fumonisins, ochratoxin A and zearalenone were established for total diet study (TDS). 13C-labelled mycotoxins matched with analytes were used as internal standards to correct the matrix effect and extraction recoveries. For the analysis of many kinds of foods in TDS, we classified matrix by the types and contents of fat, carbohydrates and protein. And then, six representative matrices (rice porridge, tomato juice, peanut butter, olive oil, milk and red pepper) were selected for the method validation. Multi-mycotoxins were extracted with the solvent and clean-up with QuEChERS for 5 matrices, however, PBS and methanol double extraction and immuno-affinity column (Myco6in1) clean-up were used for the spice samples. Liquid chromatography-tandem mass spectrometry (UPLC-Qtrap MS) with MRM scan was used for the analysis of multi-mycotoxins in the positive and negative switching mode and they were separated on the C18 column with the solvent gradient elution. The fitness for purpose of the method was evaluated with the parameters of specificity, accuracy recovery, calibration linearity, precision, method LOD and LOQ. Precision and accuracy were within the acceptable criteria of Codex Alimentarius Commission guideline (CAC/GL 71-2009). These validated methods were successfully applied to the analysis of multi-mycotoxins in the table-ready cooked foods. This research was supported by a grant (Korean Total Diet Study) from Ministry of Food and Drug Safety in 2019.