Effect of tannic acid binding on the thermal degradation behavior and product toxicity of boscalid.

[Display omitted] • The binding of tannic acid (TA) has no effect on the formation of degradation product. • The binding of TA significantly reduced the thermal degradation rate of boscalid. • Concentration ratio, pH and temperature are the main influencing factor. • Two of the degradation products were more toxic than boscalid. The effect of tannic acid (TA) binding on the thermal degradation of boscalid was studied in this work. The results revealed that TA binding has a significant impact on boscalid degradation. The degradation rate constant of bound boscalid was reduced, and its corresponding half-life was significantly prolonged compared to the free state. Four identical degradation products were detected in both states through UHPLC-Q-TOF-MS, indicating that degradation products were not affected by TA binding. Based on DFT and MS analysis, the degradation pathways of boscalid included hydroxyl substitution of chlorine atoms and cleavage of C N and C C bonds. The toxicity of B2 and B3 exceeded that of boscalid. In summary, the binding of TA and boscalid significantly affected the thermal degradation rate of boscalid while preserving the types of degradation products. This study contributed to a fundamental understanding of the degradation process of bound pesticide residues in complex food matrices. [ABSTRACT FROM AUTHOR]