噻呋酰胺在水稻及稻田环境中的残留及消解动态研究

Study on Residues and Degradation Dynamics of Thifluzamide in Rice and Paddy Field Environment

为评价噻呋酰胺在水稻和环境中的安全性,建立了噻呋酰胺在水稻植株、土壤和田水中的残留分析方法,并开展噻呋酰胺在水稻和稻田环境中的残留量及消解动态研究。进行两年三地田间试验。消解动态试验按噻呋酰胺植株中162 g a.i./hm^2施药1次,土壤中216 g a.i./hm^2施药1次;最终残留试验按162 g a.i./hm^2(高剂量)和108 g a.i./hm^2(低剂量)分别施药2次和3次,水稻收获期采样。噻呋酰胺在田水、土壤和植株中的消解半衰期分别为1.8~5.0 d、1.8~5.2 d、2.1~9.1d。噻呋酰胺在土壤、植株、谷壳和糙米中的最高残留量分别为0.322 0、2.305 2、2.142 7、0.199 7mg/kg。糙米最终残留量低于中国规定的糙米中噻呋酰胺最大残留限量(MRL)5.0mg/kg。

In order to evaluate the safety of thifluzamide in rice and paddy field environment, the method for the determination of thifluzamide residues in paddy plant, soil and water was estab- lished, and a field trial was conducted to study the residues and degradation dynamics of thi- fluzamide in rice and paddy field environment. Field trial was conducted in three locations for two years. For dissipation trial, thifluzamide was applied at the dosage of 162 g a. i. / hm2 （ paddy plant） and 216 g a. i./hm2 （soil） once. For final residue trial, thifluzamide was applied at the dosages of 162 and 108 g a. i./ha for two and three times respectively. The samples were eolleeted at harvest time. The half - lives of thifluzamide in paddy water, soil and rice straw were 1.8 - 5.0 d, 1.8 -5.2d and 2. 1 -9. ld respectively. The maximum final residues of thifluzamide in soil, riee straw, rice shell and brown rice were 0. 322 0, 2. 305 2, 2. 142 7, 0. 199 7mg/kg, respee- tively. The results showed that the residues of thifluzamide in brown rice were less than the MRL in China （5.0mg/kg） .