露地土壤-芹菜体系噻虫嗪及其代谢产物噻虫胺残留与消长规律研究

Study on residues, growth and decline of thiamethoxam and its metabolite clothianidin in open field of soil-celery system

中文关键词:  噻虫嗪  噻虫胺  芹菜  残留  农产品安全

英文关键词:thiamethoxam  clothianidin  celery  residue  agricultural product safety

中文摘要:

      目的 探明露地土壤-芹菜体系噻虫嗪及其代谢产物噻虫胺的残留与消长规律。方法 在河北张家口开展露地芹菜噻虫嗪、噻虫胺的最终残留和消解动态试验, 样品通过10 mL乙腈提取, 提取溶液经50 mg N-丙基乙二胺和3 mg多壁碳纳米管净化后, 采用气相色谱-串联三重四极杆质谱法在质谱多反应监测模式下检测噻虫嗪和噻虫胺的残留量。结果 噻虫嗪和噻虫胺在芹菜上的回收率范围分别为80.7%~96.5%、76.1%~103.9%; 在土壤上分别为74.0%~96.4%、84.9%~86.7%; 最终残留试验中, 用药后第10 d噻虫嗪在芹菜残留量为0.188 mg/kg, 低于国家规定的最大残留限量(maximum residue limit, MRL), 噻虫胺为0.112 mg/kg, 超出其MRL值。噻虫嗪在芹菜上的消解动力学方程为C=2.7244e?0.246t, r2为0.9094, 半衰期为2.82 d。噻虫嗪在土壤中沉积量呈现先上升再下降趋势, 峰值为0.330 mg/kg; 噻虫胺在土壤中未见明显趋势。结论 噻虫嗪在芹菜上施用后的残留风险较低, 但其代谢产物噻虫胺有残留风险。噻虫嗪与噻虫胺施用对土壤环境影响较小。

英文摘要:

      Objective To investigate the residues, growth and decline of thiamethoxam and its metabolite clothianidin in the open field soil-celery system. Methods The final residue and digestion dynamic test of thiamethoxam and clothianidin in open field celery was carried out in Zhangjiakou, Hebei Province. Samples were extracted with 10 mL of acetonitrile and then the extraction solution was purified by 50 mg of N-propyl ethylenediamine and 3 mg of multi-walled carbon nanotubes, and the residues of thiamethoxam and thiamethoxam were detected by gas chromatography-tandem triple quadrupole mass spectrometry in mode of multi-reaction monitoring. Results The recovery ranges of thiamethoxam and clothianidin in celery were 80.7%?96.5% and 76.1%?103.9%, respectively; and the values were among 74.0%?96.4% and 84.9%?86.7% in soil, respectively. In the final residue test, the residue level of thiamethoxam in celery was 0.188 mg/kg on the 10th day after dosing, which was lower than the national maximum residue limit (MRL), and that of clothianidin was 0.112 mg/kg, which exceeded its MRL value. The digestion kinetic equation of thiamethoxam on celery was C=2.7244e?0.246t, r2 was 0.9094, and the half-life was 2.82 d. The amount of thiamethoxam deposited in soil firstly increased and then decreased, with the peak value of 0.330 mg/kg. No significant trend of clothianidin was observed in soil. Conclusion The residual risk of thiamethoxam on celery is low, but its metabolite clothianidin exhibits the residual risk. The application of thiamethoxam and clothianidin has little impact on soil environment.