Residues and dissipation dynamics of tricyclazole and azoxystrobin in rice plant and field

Objective To study the residues and dissipation dynamics of tricyclazole and azoxystrobin in rice plant, soil and paddy water.

Method Rice samples were extracted with acetonitrile or dichloromethane, the extracts were enriched and then analyzed by high performance liquid chromatography(tricyclazole) and gas chromatography(azoxystrobin).

Result The limits of quantification(LOQ) were 0.05 and 0.01 mg·L^-1, the average recovery rates ranged from 78.5% to 100.8% and 73.9% to 109.7%, and the relative standard deviations (RSD) ranged from 1.0% to 12.9% and 3.1% to 12.9% for tricyclazole and azoxystrobin respectively. The dissipation dynamics of tricyclazole and azoxystrobin residues in rice plant, soil and paddy water fitted the first-order kinetic equations. The dissipation half-lives of tricyclazole and azoxystrobin in rice ranged from 2.4 to 13.1 and 4.3 to 16.1 d respectively.

Conclusion Tricyclazole and azoxystrobin are both easily degradable pesticides. The sensitivity, accuracy and precision of the detection methods all meet the requirements for pesticide residue analysis.