【作者】 徐彦军；

【导师】 吴学民； 刘丰茂；

【作者基本信息】 中国农业大学 ， 农药学， 2014， 博士

【摘要】 药食同源作物由于种植面积小或经济回报率低等原因,在这些作物上进行正式登记的农药品种较少。农业生产实践中,种植者为提高产量,凭经验大量使用非登记农药,致使作物中农药残留问题较为普遍且残留水平较高,在一定程度上影响了消费者的健康安全。薄荷作为一种药食同源作物,目前在我国还没有登记用药。本文建立了薄荷中33种农药的多残留分析方法,并通过调查国内薄荷主产地田间实际用药品种及其施药剂量,在四个种植地区进行了薄荷上三唑酮、氰戊菊酯、杀螟硫磷三种农药的残留田间试验,通过膳食摄入风险评估,对薄荷作物上这几种农药的用药安全性进行评价,同时研究了薄荷在加工过程中的农药残留转移规律。研究结果可为提高我国药材质量控制提供依据,同时探索一种我国相关小作物农药最大残留限量的作物间外推新模式,为小作物MRL制订提供一种新的思路。本研究的主要内容有：1.薄荷中33种农药多残留分析方法的建立。以环己烷／乙酸乙酯超声提取,氨基-石墨化碳固相萃取柱净化,GC-ECD检测。结果表明33种农药在薄荷中0.01～1mg/kg添加水平时添加回收率为72.1%～113.9%,相对标准偏差低于19%, LOD在0.1～80μg/kg之间,LOQ在0.5～200μg/kg之间。2.三唑酮、氰戊菊酯、杀螟硫磷三种农药在薄荷上施用后的用药安全评价。参照农田实际施药调查以及在其它作物上登记且防治与薄荷上相同病虫害的农药品种及施药GAP来确定薄荷作物上的施药GAP,在北京、河北、山东、江西四地进行田间残留试验。结果表明三种农药在薄荷上的消解动态方程都符合一级反应动力学方程,氰戊菊酯在江西和山东两地薄荷上的消解比河北和北京稍快,杀螟硫磷和三唑酮在四地的消解情况较为相似,杀螟硫磷四地的半衰期为1.0～2.4天,三唑酮四地的半衰期为0.9～3.9天,氰戊菊酯为1.9～4.5天。最终残留结果显示,施药量越高,最终残留水平也越高,当采收间隔期为20天时,薄荷中三唑酮的最高残留量为1.51mg/kg,氰戊菊酯为0.29mg/kg,杀螟硫磷为0.60mg/kg。进一步对薄荷上这3种农药的膳食摄入风险进行评估,结果显示三唑酮的慢性风险商为16.03%,氰戊菊酯的慢性风险商为73.46%,杀螟硫磷的慢性风险商为311.43%,3种农药均无短期膳食摄入风险,由此可以得出结论：三唑酮和氰戊菊酯的用药在薄荷上是安全的,但不建议杀螟硫磷在薄荷上施用。3.三种农药在薄荷加工过程中的残留转移规律：根据三唑酮、氰戊菊酯、杀螟硫磷在薄荷加工过程中的变化情况,对几种农药在薄荷中的残留转移及其膳食风险进行评价。结果表明,三唑酮、氰戊菊酯、杀螟硫磷从植株向茶汤的浸泡转移因子分别为0.47、0.46和0.44。薄荷煎药后大部分农药随着煎药过程降解,三唑酮、氰戊菊酯、杀螟硫磷的煎药加工因子分别为0.21、0.10和0.08。薄荷炒制烹饪后大部分农药也随着烹饪过程降解,三唑酮、氰戊菊酯、杀螟硫磷的炒制烹饪加工因子分别为0.41、0.25和0.10。薄荷植株中大部分水分随着干燥过程而损失,因此干燥加工后的薄荷中农药残留量增加,食用风险加大,三唑酮、氰戊菊酯、杀螟硫磷的干燥加工因子分别为1.97、1.51和3.66。薄荷加工后的膳食风险评估结果与初级农产品的风险评估相比较,差异并不明显,只是施用三唑酮的薄荷干燥后其急性风险商为106%,会对食用的一般人群产生一定的风险,除杀螟硫磷外,三唑酮和氰戊菊酯在薄荷上的用药不会对食用薄荷茶汤、薄荷药汤、炒制烹饪薄荷的一般人群产生不可接受的风险。更多还原

【Abstract】 The pesticides registered in crops which can use both as food and medicine are very few due to its small planting area or low economic return to the producers. However the pesticide application is unavoidable to prevent the disease or pest damage in agricultural practices. Thus serious pesticide residue problem on these crops was caused because of the improper use of unregistered pesticides..Mint is one of the medicinal and edible crops.Currently,there is no pesticide registered in mint. In this study, a multi-residue analytical methods of33kinds of pesticides in mint was established,and based on pest and disease control on mint in practical production, triadimefon, fenvalerate, fenitrothion were selected to conduct field trials in four regions of China. Dietary intake risk assessment of those pesticides in mint was evaluated,and meanwhile,the behavior of pesticide residue during mint processing was also studied.The results of the study could give a reference of Chinese government to set MRL of pesticides used in mint, and to investigate a feasible way to extrapolate the pesticide application between minor crops and major crops. The main results are as follows.1. An analytical method was developed to determine33pesticides residues in mint. The samples were extracted with cyclohexane/ethyl acetate based on ultrasonic extraction, purified by amino-graphite carbon solid phase extraction (SPE) and detedcted by GC-ECD. Results showed that recoveries of33pesticide residues in mint ranged from72.1to113.9%with relative standard deviations (RSDs) less than19.2%. Limits of detection (LODs) and limits of quantification (LOQs) were0.1-80μg/kg and0.5～200μg/kg, respectively.2. The safety evaluation was conducted for application of triadimefon, fenvalerate and fenitrothion on mint according to the GAP used in other crop whose pest or disease was the same as in mint. The field trials of triadimefon, fenvalerate, fenitrothion on mint were conducted in four regions including Beijing, Hebei, Jiangxi and Shandong in2013. Results showed that the degradation of three pesticides fitted for the first order kinetic equation. The dissipation of fenvalerate in Hebei and Beijing was faster than that in Jiangxi and Shandong. The dissipation of fenitrothion and triadimefon were similar and the half-life of fenitrothion was1.0～2.4day and for triadimefon was0.9～3.9day. The residue levels increased with the increasing of pesticide application dosage. When the harvest interval was20days, the maximum residues of triadimefon, fenvalerate and fenitrothion was up to1.51mg/kg,0.29mg/kg and0.60mg/kg, respectively. The chronic dietary intake risk quotient of, fenvalerate and fenitrothion exposure on mint was16.03%,73.46%and311.43%, and all three pesticides had no short-term dietary intake of pesticide risk, thus it can be concluded that triadimefon and fenvalerate are safe when used on mint with experiment dosage,however, fenitrothion is not suggested to be used on mint considering the high chronic dietary intake risk quotient.3. The behavior and risk assessment of pesticides in mint during processing were investigated. Results showed the transfer rate of triadimefon, fenvalerate and fenitrothion during immersion processing were0.47,0.46and0.44, respectively. Most of pesticide residues transferred to air or degraded during decoction processing. The transfer rate of triadimefon, fenvalerate and fenitrothion during decoction processing were0.21,0.10and0.08, respectively. The transfer rate of triadimefon, fenvalerate and fenitrothion during frying and cooking were0.41,0.25and0.10, respectively. The pesticide residues were increased during dry processing because of the lossing of moisture. The transfer rate of triadimefon, fenvalerate and fenitrothion during dry processing were1.97,1.51and3.66, respectively. The differences of Mint dietary risk assessment after processing comparing with the agricultural commodities were not significant except the application of triadimefon during mint drying had a certain acute risk to general people.The results of the risk assessment showed that except fenitrothion, the influences of triadimefon and fenvalerate on mint, mint tea, fried and cooked mint and dried mint are acceptable for general population.更多还原