Abstract: 【Objective】The objective of this study is to investigate the chiral stability of dinotefuran racemate (Rac-dinotefuran) and enantiomers (S-dinotefuran and R-dinotefuran) in methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, dichloromethane, ultrapure water and β-cyclodextrin solution under xenon lamp, natural light, and dark, determine chiral neonicotinoid dinotefuran used extensively in China, and to accurately evaluate its efficacy and environmental safety.【Method】The samples were collected periodically during the whole experimental process. Dinotefuran enantiomers were analyzed by high performance liquid chromatography/diode array detector (HPLC/DAD) with amylose tris-3, 5-dimethylphenylcarbamate as chiral stationary phase and n-hexane/methanol/ethanol (85/10/5,v/v/v) as mobile phase. The ultraviolet detection wavelength of the DAD was identified at 270 nm. The column temperature was set at 30℃ and the injection volume was 20 µL. The retention times of S-dinotefuran and R-dinotefuran were 8.3 and 9.7 min. The quantification of dinotefuran enantiomers was made by using external standard method.【Result】No transformation was observed between S-dinotefuran and R-dinotefuran in methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, dichloromethane, ultrapure water and β-cyclodextrin solution under xenon lamp, natural light and dark conditions. Dinotefuran did not undergo enantioselective degradation by the student’s paired t-test for the Rac-dinotefuran in all the solvents. The enantiomer fractions (EF) were 0.4746-0.5116. However, Rac-dinotefuran, S＞acetonitrile＞ethyl acetate≈isopropanol ≈ethanol＞methanol＞ultrapure water＞β-cyclodextrin solution. The degradation of dinotefuran enantiomers in the organic solvents was faster than in the aqueous solutions and the estimated half-lives were 3.3-3.6 h and 1.2-2.3 h, respectively. The photodegradation followed first-order kinetics mode and the correlation coefficients were ranged from 0.9550 to 0.9959. Rac-dinotefuran, S-dinotefuran and R-dinotefuran showed no obvious degradation in dichloromethane, acetonitrile, ethyl acetate, isopropanol, ethanol, methanol, ultrapure water, and β-cyclodextrin solution under natural light and dark during the whole experimental process. The measured concentration and the corresponding relative standard deviation were 9.5-10.4 mg?L^-1 and 1.0%-3.2% under natural light, whereas they were 9.5-10.5 mg?L^-1 and 1.4%-2.8% under dark. 【Conclusion】Dinotefuran enantiomers were chiral configuration stability in methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, dichloromethane, ultrapure water, and β-cyclodextrin solution under xenon lamp, natural light and dark condition conditions at (25±2)℃. The qualitative and quantitative analysis, efficacy and environmental safety assessment were accurate under these conditions.-dinotefuran and R-dinotefuran were degraded rapidly in the solvents under xenon lamp. The order of the degradation rate was dichloromethane

Key words: dinotefuran, enantioselectivity, photodegradation, transformation