Residue behaviors and dietary risk assessment of dinotefuran and its metabolites in Oryza sativa by a new HPLC–MS/MS method

In this study, we developed a new method to detect dinotefuran and its metabolites (UF and DN) in Oryza sativa (Rice) by HPLC–MS/MS in multiple reaction monitoring (MRM) modes. The recovery rates for dinotefuran, UF and DN were 82.3–85.8%, 83.7–89.0%, and 81.6–90.2%, respectively. The dissipation kinetics of dinotefuran in rice followed a combined first + first kinetic model, where the half-lives of dinotefuran and its metabolites were determined to be between 0.5 and 2.3 days. The dinotefuran residue in brown rice sampled at day 7, 14, and 21 after the last application was 0.4131 mg/kg with a very low risk quotient (RQ) value. We recommend that the safety interval of application for rice is 7 days. The method developed in this study is simple and rapid, with high accuracy and precision which meet the requirements for quantitative analysis of dinotefuran in rice.