马拉硫磷在香蕉、土壤上的残留动态及安全性评价

Residual Dynamics and Safety Assessment of Malathion in Banana & Orchard Soils

采用气相色谱法及田间试验方法．研究马拉硫磷在香蕉和土壤中的残留降解动态。结果表明：马拉硫磷在香蕉上的原始沉积量与施用剂量密切相关．加倍剂量的原始沉积量比推荐剂量的高出80．2％．两种处理的降解速率均非常迅速．施用后7d残留量均〈0．005mg／kg。马拉硫磷在香蕉园土壤上的降解规律符合一级动力学关系，降解动态方程为C=0．0963·e-0.1184t，半衰期（T1/2）为5．5d，降解99％所需要的时间（T0.99）为35．9d。距第2次施药后61--65d，最终在香蕉及土壤上均未检出马拉硫磷残留（检出限为0．005mg／kg）。在福建蕉区上科学、合理施用马拉硫磷，最终产品质量可符合GB2763—2012、NY/T750—2011中规定的MRL要求．同时最终对蕉园土壤环境不会造成长期污染。

The residue dynamics of malathion in banana and orchard were studied by the methods of GC and the field experiments. The results showed that the original sediment of malathion in banana was closely related to different dosage, which of the double dosage treatment was 80.2% higher than the recommended dose. Malathion was degraded at a fast rate in the banana, and the residue were less than 0.005 mg/kg after being applied into banana for 7 d. The rule of malathion degradation in the soil was fit with first-order kinetics, and the equation was C=0.096 3·e-0.1184, with Tit2 and T0.99 were 5.5 d and 35.9 d, respectively. The final residues in banana and orchard soil had not been detected（detection limit of 0.005 mg/kg） after the second application for 61--65 d. Scientifically and rationally use of malathion in Fujian, the final product quality could accord with the maximum residue limit（MRL） established in GB 2763-2012 and NY/T 750-2011, and eventually did not cause long-term pollution of soil environment.