Department of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
Environ Monit Assess. 2010 Jun;165(1-4):685-92. doi: 10.1007/s10661-009-0979-5. Epub 2009 Jun 3.
To analyze the dynamic degradation and final residues of acephate and its metabolite methamidophos, field-experiments with pakchoi (Brassica campestris L.) in open field and greenhouse were carried out in Beijing, China in 2004 and 2005. The degradation dynamics and final residues were determined by gas chromatography (GC) equipped with a pulsed flame photometric detector and GC coupled to mass spectrometry (MS)/MS after acephate was applied on open field and green house pakchoi (B. campestris L.). The dynamic degradation results showed that the half-lives of acephate and methamidophos in open field pakchoi were 1.36 days with dynamic degradation equation C( t ) = 133.01e( - 0.5107t ), and 2.86 days with C( t ) = 6.5753e( - 0.2422t ), respectively. While the half-lives of acephate and methamidophos in the greenhouse were 1.07 days with C( t ) = 59.134e( - 0.4353t ) and 0.79 days with C( t ) = 0.2703e( - 0.2595t ), respectively. The final residue analysis demonstrated that >50% of total methamidophos were resulted from the degradation of acephate 7 and 18 days after it was applied on the greenhouse pakchoi, respectively. While in the open-field pakchoi, >90% of total methamidophos was found to be the metabolite of acephate.
2004 年和 2005 年，在北京的田间和温室中，以小白菜（ Brassica campestris L.）为实验材料，进行了田间和温室实验，分析了乙酰甲胺磷及其代谢物甲胺磷的动态降解和最终残留情况。在田间和温室小白菜（B. campestris L.）上施药后，采用气相色谱（GC）-脉冲火焰光度检测器和 GC-串联质谱（MS/MS）法，对乙酰甲胺磷和甲胺磷的降解动态和最终残留量进行了测定。动态降解结果表明，乙酰甲胺磷和甲胺磷在田间小白菜中的半衰期分别为 1.36 天和 2.86 天，降解方程分别为 C(t)=133.01e(-0.5107t)和 C(t)=6.5753e(-0.2422t)。而在温室小白菜中，乙酰甲胺磷和甲胺磷的半衰期分别为 1.07 天和 0.79 天，降解方程分别为 C(t)=59.134e(-0.4353t)和 C(t)=0.2703e(-0.2595t)。最终残留分析表明，施药 7 天和 18 天后，温室小白菜中甲胺磷的总残留量中有>50%来源于乙酰甲胺磷的降解，而在田间小白菜中，>90%的甲胺磷总残留量被发现是乙酰甲胺磷的代谢物。
