4％杀螟丹在稻田生态环境中的降解与残留

研究了4%杀螟丹粒剂在水稻植株、稻米、稻壳、稻田水和土壤中的残留及消解动态.采用石油醚提取,液液分配净化,气相色谱(GC-ECD)测定,结果表明:杀螟丹在稻田土壤中的平均添加回收率为93.25%～106.85%,相对标准偏差为5.99%～8.17%;在水样中的平均添加回收率为95.43%～103.68%,相对标准偏差为2.64%～8.48%;在稻杆中的平均添加回收率为90.81%～100.8%,相对标准偏差为3.00%～6.89%;在稻壳中的平均添加回收率96.77%～101.09%,相对标准偏差2.75%～6.32%;在稻米中的平均添加回收率为92.89%～97.71%,相对标准偏差为2.98%～8.09%.杀螟丹的最低检出量为1.0×10~(-11)g,土样、水样中杀螟丹的最低检出浓度分别为0.001 mg/kg和0.000 25 mg/L,在水稻稻杆、稻米和稻壳中的最低榆出浓度均为0.005 mg/kg.湖南长沙和云南昆明两地残留消解动态试验结果表明:杀螟丹在稻田土壤、水样和植株中的半衰期分别为:6.8～9.9 d,7.4～7.8 d和7.6～8.9 d.

Degradation and Residue of 4% Cartap on Ecological Environment of Paddyfield

The residue and degradation dynamic of 4% cartap in rice plant,rice,rice hull,paddyfield water and paddyfield soil was studied.Samples were extracted by petroleum ether,and then purified by liquid-liquid partition and determined by gas chromatography (GC-ECD).The results indicated that the average fortified recovery of cartap in paddyfield soil,paddyfield water,rice stem,rice hull and rice was 93.25%～106.85%,95.43%～103.68%,90.81%～100.8%,96.77%～101.09% and 92.89%～97.71%,respectively,and the relative standard deviation(RSD) of which was 5.99%～8.17%,2.64%～8.48%,3.00%～6.89%,2.75%～6.32%and 2.98%～8.09%,respectively.The minimum detectable amount of cartap was 1.0×10~(-11) g,and the minimum detectable concentration of cartap in paddyfield soil,paddyfield water, and rice plant (stem,hull and rice)Was 0.001 mg/kg,0.000 25 mg/L and 0.005 mg/kg, respectively.The results from field experiment of degradation dynamic in Changsha and Kunming indicated that the half-life of cartap in paddyfield soil,paddyfield water and rice plant was 6.8～9.9 d,7.4～7.8 d and 7.6～8.9 d,respectively.