摘要
用气相色谱法测定了溴氰菊酯和辛硫磷混合制剂在甘蓝上的消解动态及最终残留量。溴氰菊酯和辛硫磷在甘蓝上的半衰期分别为3d,8h,以每亩40mL 的剂量在甘蓝生长后期,喷施50%溴氰菊酯和辛硫磷混合制剂2次(间隔5d),最后一次施药距采收期5～10d,溴氰菊酯在甘蓝边叶上的残留量为0.012～0.009ppm,在心叶上的残留量为0.003～0.001ppm;而辛硫磷则没有检出。
GC-9A eguipped with ECD and FID detector was used to measure the residue and degradation of deltamethrin and phoxim in cabbage respectively. The experimental results of one year in two places show the degradation's speed of deltamethrin and phoxim in cabbage.The halftimes of deltamethrin and phox- im in cabbage were three days and eight hours respectively.When 40mL/mu 50% mixture EC of deltamethrin and phoxim were applied twice during the later per- iod of the cabbage,and the pre-harvest interval of the last application was 5 to 10 days,the residue of deltamethrin in the outside leaves of the cabbage was 0.0125ppm～0.0094ppm and in the inside leaves of the cabbage were 0.0034ppm～ 0.0011ppm,and the residue of phoxim in cabbage has not detected。
