异丙隆在水稻和稻田土壤、水中的残留量和降解动态研究

研究异丙隆在水稻、土壤、田水中的残留分析方法及其消解动态和最终残留量。样品以丙酮提取、净化后采用气相色谱法-氮磷检测器（GC—NPD）毛细管柱进行测定。水田添加0．005、1．00mg／kg，土壤、水稻添加0．05、1．00mg／kg，添加回收率在77．9％-118．4％之间，变异系数为2．1％～11．2％。异丙隆在田水、土壤的消解动态没有明显差异，平均半衰期分别为413、5-3d，在稻秆中消解较慢，平均半衰期为8．3d。异丙隆24％可湿性粉剂，按900ga．i.／hm^2用量，在直播水稻田水稻播种后施药1次，收获时异丙隆在土壤、稻杆和稻谷中的残留量均低于0．05mg／kg。

Dynamics and Degradation of Isoproturon in Rice,Soil and Water

The method for residue analysis of isoproturon, its degradation and residue in rice, soil and water were studied. The samples were extracted with acetone, then cleaned up, the extracts were analyzed by GC with NPD using HP-5 capillary column. The results showed that： at the spike level of 0.005, 0.05 and 1.00mg/kg, the recoveries were 77.9%-118.4%, the coeffi- cients of variation were 2.1%-11.2%. The dissipation rate was slower in straw than in water and soil, the residual dynamics had no evident difference between in water and soil. the average half-lifes （T1/2） in water and soil were 4.3d and 5.3d, in straw was 8.3d respectively. The residue levels in soil, straw and rice seeds were lower than 0.05mg/kg at the harvest time, when isoproturon 24% WP was applied with the dosage of 900g a.i./hm^2 to the direct seeding rice fields for one time.