Residue Analysis And Digestion Dynamics Study Of 25% Fluorohexamine Suspension On Tobacco

Flumetralin is a kind of contact and a partial absorption of axillary bud inhibitors, primarily used to inhibit tobacco suckers. In this research, we established a gas chromatography(GC-?ECD) method to determine the residues of flumetralin in soil, green tobacco leaves and cured tobacco leaves matrix. This paper studied the final residues and degradation dynamics data of 25% flumetralin suspension in tobacco, and provided a theoretical basis for the residues detection and safe handing of flumetralin in tobacco environment.Flumetralin from soil, green tobacco leaves and cured tobacco leaves samples were extracted with acetonitrile. Green tobacco leaves were purified by octadecyl bonded silica(C18), N-propyl-ethylenediamine(PSA) and carbon and graphite(GCB), cured tobacco leaves samples were purified by florisil SPE column. The results showed that the external standard curve presented a good linearity between 0.1 and 10 ?g/mL with the correlation coefficient of 0.997. Recoveries in soil, green tobacco leaves and cured tobacco leaves were 77.72~100.9%, 86.37~99.68% and 84.83~104.2% respectively, with relative standard deviation(RSD) <7.88%. Results showed that accuracy, precision and sensitivity of the method are conformity with the Chinese pesticide residues test standards(NY/T 788-2004).The field trials of 25% flumetralin(SC) were performed in Guizhou and Hunan province in tobacco during the agricultural season in 2014 and 2015. Residues of flumetralin in tobacco and soil were carried out. The results indicated that the flumetralin residues are below the GRLs(5 mg/kg) in cured tobacco leaves at the recommended dosage and administration of the established field experiments.Moreover, this paper carried out experiment of flumetralin in soil degradation in laboratory simulation. Discussed the degradation behavior of flumetralin in Guizhou, Shandong and Anhui three different soil, and the effect of different moisture content, organic matter content and microbial content in soil for the degradation of flumetralin. The results showed that the appropriately high water content, microbes and organic matter can promote the degradation of flumetralin in soil. The degradation rate of flumetralin in Anhui soil is fastest, and in Guizhou soil is slowest.