Degradation and ozonolysis pathway elucidation of deoxynivalenol.

To explore the degradation products and ozonolysis pathway of deoxynivalenol (DON), DON (~50 mg/L) in acetonitrile solution was treated by ozone at a concentration of 10.84 g/m and a flow rate of 80 mL/min for the times ranging from 0 to 9 min. The results showed that DON concentration rapidly reduced from 51.11 mg/L to 14.97 mg/L within 9 min of ozone exposure with 98.30% of degradation rate, and the ozonolysis of DON followed the first-order kinetic model. Four ozonolysis products of DON were identified based on the analysis of Liquid chromatography-quadrupole time-of-flight mass spectra (LC-QTOF/MS). Their structures were similar to that of DON, while the double bond at C9-C10, 12,13-epoxide ring, and the hydroxyl group at C3 or C7 of DON were all destroyed by ozone. It is deduced that the toxicity of ozonolysis products significantly reduced based on the relationship between structure and toxicity of DON. The ozonolysis pathway of DON followed the Criegee reaction mechanism of ozone according to the chemical structures, accurate mass and molecular formulas of these products.