【摘要】 本研究探索了丙环唑对普通白菜株高和产量的影响及其残留动态,为建立普通白菜生产中丙环唑安全有效使用技术规程和残留限量标准提供科学依据。两个实验剂量分别为高浓度(375 g a.i./hm~2)和低浓度(250 g a.i./hm~2)。结果表明,喷施后7 d,高、低剂量处理组株高比对照组分别下降17.19%和15.63%,达显著水平;喷施后14 d,高、低剂量处理组株高比对照组分别下降12.24%和7.35%,达显著水平;而产量下降均未达显著水平。丙环唑消解动态符合一级动力方程,半衰期为1.98 d。喷施后7~14 d,丙环唑终残在0.380 9~0.032 7 mg/kg,膳食暴露风险熵在10.42~7.56,处于可接受范围;喷施后第14 d的残留低于日本标准。广州农贸市场和超市中的普通白菜丙环唑残留以及膳食暴露风险研究表明,丙环唑残留监测值99位点为0.013 7 mg/kg,拟合残留值99位点为0.011 3 mg/kg,残留暴露风险熵99.9位点为7.44,处于可接受范围。按照风险最大化原则,参考农药残留限量制定规则,以1 mg/kg和0.01 mg/kg为最高和最低残留限量理论值,对消费者膳食暴露风险保护水平分别为6.44、13.56。建议将1 mg/kg作为普通白菜丙环唑残留限量标准。更多还原

【Abstract】 The effect of propiconazole on plant height and yield of pak-choi and its residue behavior were studied. The proposed study would provide scientific grounds for the development of safe and effective technical regulations for propiconazole application during pak-choi growing and establishment of maximum residue limit(MRL). Field trials were carried at two dosages: 375 g a.i./hm~2(high dosage) and 250 g a.i./hm~2(low dosage). Seven days after spray, the plant height decreased significantly by 17.19% and 15.63% for high dosage and low dosage group respectively compared with the reference. Fourteen days after spray, the plant height decreased significantly by 12.24% and 7.35%. The decrease of yield did not reach a significant level. Dissipation of propiconazole was fitted to a first order kinetics equation with half-life of 1.98 d. 7–14 d after spray, the terminal residue of propiconazole was 0.380 9–0.032 7 mg/kg and dietary exposure risk quotients were within acceptable range of 7.56–10.42. Fourteen days after spray, residue of propiconazole was below MRL of Japan. Residue level and dietary exposure risk of propiconazole in pak-choi samples from the agricultural trade market and supermarket in Guangzhou were investigated. Results revealed that the 99 site point of monitoring and fitted value of propiconazole were 0.013 7 mg/kg and 0.011 3 mg/kg respectively, with residue exposure risk quotient of 99.9 site point value as 7.44. The dietary exposure risk of market pak-choi sample was acceptable. According to the principle of setting MRL for pesticide and to evaluate maximum risk, 1.00 mg/k and 0.01 mg/kg were used as maximum and minimum theoretical MRLs. The protection factors based on dietary exposure risk assessment for consumer was of 6.44 and 13.56, respectively. It is suggested that 1 mg/kg is applied as the MRL of propiconazole in pak-choi.更多还原