氟環(huán)唑在稻田環(huán)境中的殘留消解及土壤吸附研究
發(fā)布時間：2018-12-12 02:37
【摘要】：氟環(huán)唑是一種三唑類的廣譜殺菌劑。目前國內(nèi)外有關(guān)于氟環(huán)唑在小麥、蘋果、梨與葡萄上的殘留消解研究報道,而關(guān)于稻田環(huán)境中氟環(huán)唑的殘留消解,以及在土壤中的吸附行為研究報道甚少。本文主要研究了氟環(huán)唑在稻田生態(tài)環(huán)境中(稻田田水、稻田土壤和水稻植株)的殘留降解行為及其在土壤中的吸附規(guī)律,為氟環(huán)唑在稻田環(huán)境中的安全使用提供科學的依據(jù)。主要結(jié)論如下：(1)建立了氟環(huán)唑在稻田環(huán)境樣品中殘留量檢測的簡易實驗室前處理方法方法和HP-5柱分離-ECD檢測器檢測的氣相色譜分析方法。田水樣品用二氯甲烷：丙酮混合液提�。凰局仓陿悠酚枚燃淄椋阂译婊旌先芤禾崛�；稻田土壤、稻殼、稻米樣品用甲醇：石油醚混合溶液提取,經(jīng)弗羅里硅土柱凈化；采用氣相色譜電子捕獲檢測器測定。氟環(huán)唑的添加回收率實驗是在田水、田土中添加0.05-1. OOmg/kg氟環(huán)唑標樣；水稻植株、稻殼、稻米中添加0.025-0.50mg/kg氟環(huán)唑標樣,其平均回收率為78.5%-101.1%,相對標準偏差為2.0%-7.7%,符合農(nóng)藥殘留量分析與檢測的技術(shù)要求。(2)研究了氟環(huán)唑在稻田環(huán)境中的消解動態(tài)和最終殘留。實驗結(jié)果表明：可以用一級動力學方程(C,=Coe-kl)來描述氟環(huán)唑在水稻環(huán)境中的消解動態(tài)。選擇南北不同氣候地點,于2013-2014年在長沙和北京郊區(qū)進行了氟環(huán)唑的田間試驗,氟環(huán)唑在稻田田水、土壤與水稻植株中的平均半衰期分別是3.60d、13.38d、4.20d。因此表明氟環(huán)唑?qū)儆谝紫廪r(nóng)藥(T1/230d)。最終殘留實驗結(jié)果表明：氟環(huán)唑施藥劑量為900g／hm2,施藥次數(shù)2次,最后一次施藥后間隔28d時,氟環(huán)唑在稻米中的殘留量均沒有超過MRL值(0.05 mg/kg).(3)氟環(huán)唑在五種不同的供試土壤中的吸附平衡時間是24h,吸附原理可以用Freundlich等溫吸附方程擬合,吸附能力大小是：湖南紅壤山東褐土)黑龍江黑土)重慶紫土)湖南河潮土。在五種土壤中的吸附都表現(xiàn)為物理吸附(AG40 kJ/mol)。氟環(huán)唑的吸附量隨pH值的變化而變化,當pH值從7上升至11時,吸附量也是隨著增大的。當土壤環(huán)境溫度為25℃時,氟環(huán)唑的吸附量達到最高點。當鈣離子濃度在0. 05mol/L時,氟環(huán)唑的吸附量是最大的。陽離子表面活性劑CTAB對氟環(huán)唑在土壤中的吸附起抑制作用,陰離子表面活性劑SDBS對氟環(huán)唑在土壤中的吸附先起抑制作用后起促進作用。
[Abstract]:Fluoxazole is a kind of wide spectrum fungicides of triazole. At present, there are some reports on the residue digestion of fluoxazole in wheat, apple, pear and grape, but there are few reports on the residual digestion of fluoxazole in paddy field environment and the adsorption behavior in soil. In this paper, the residual degradation behavior of fluoxazole in the ecological environment of paddy field (paddy field water, paddy field soil and rice plant) and its adsorption in soil were studied, which provided a scientific basis for the safe use of fluoxazole in paddy field environment. The main conclusions are as follows: (1) A simple laboratory pretreatment method for the determination of flucyclazole residues in environmental samples of paddy fields and a gas chromatographic analysis method for HP-5 column separation and ECD detector detection have been established. Field water samples were extracted with dichloromethane: acetone mixed solution, rice plant samples were extracted with dichloromethane and acetonitrile mixed solution, paddy soil, rice husk and rice samples were extracted with methanol: Petroleum ether mixed solution and purified by Florion silica column. Gas chromatographic electron capture detector was used. The recovery rate of fluoxazole was 0.05-1 in field water and field soil. OOmg/kg fluoxazole standard sample; The average recovery was 78.5% and 101.1%, and the relative standard deviation was 2.0-7.7%, and the average recovery rate was 78.5% -101.1%, and the relative standard deviation was 2.0-7.7%. It meets the technical requirements of pesticide residue analysis and detection. (2) the degradation dynamics and final residues of fluoxazole in paddy field environment were studied. The experimental results show that the first-order kinetic equation (C _ (C) -Coe-kl) can be used to describe the digestion dynamics of fluocyrazole in rice environment. A field trial of fluoxazole was carried out in Changsha and the suburbs of Beijing from 2013 to 2014. The average half-life of fluoxazole in paddy field, soil and rice plant was 3.60 days, 13.38 days and 4.20 days, respectively. Therefore, flucyclazole belongs to easily digestible pesticide (T 1 / 230 d). The results of the final residue test showed that the dose of fluoxazole was 900g / hm ~ (2), the number of times of application was 2 times, and the interval of 28 days after the last application was 28 days. The adsorption equilibrium time of flucyclazole in five different soils was 24 h, and the adsorption principle could be fitted by Freundlich isothermal adsorption equation. The adsorption capacity is: red soil, Shandong cinnamon soil, Heilongjiang black soil, Chongqing purple soil) Hunan river tidal soil. Physical adsorption (AG40 kJ/mol) was observed in the five soils. The adsorption capacity of flucyclazole changed with the change of pH value. When the pH value increased from 7 to 11:00, the adsorption capacity also increased. When the soil temperature was 25 鈩，
本文編號：2373739
[Abstract]:Fluoxazole is a kind of wide spectrum fungicides of triazole. At present, there are some reports on the residue digestion of fluoxazole in wheat, apple, pear and grape, but there are few reports on the residual digestion of fluoxazole in paddy field environment and the adsorption behavior in soil. In this paper, the residual degradation behavior of fluoxazole in the ecological environment of paddy field (paddy field water, paddy field soil and rice plant) and its adsorption in soil were studied, which provided a scientific basis for the safe use of fluoxazole in paddy field environment. The main conclusions are as follows: (1) A simple laboratory pretreatment method for the determination of flucyclazole residues in environmental samples of paddy fields and a gas chromatographic analysis method for HP-5 column separation and ECD detector detection have been established. Field water samples were extracted with dichloromethane: acetone mixed solution, rice plant samples were extracted with dichloromethane and acetonitrile mixed solution, paddy soil, rice husk and rice samples were extracted with methanol: Petroleum ether mixed solution and purified by Florion silica column. Gas chromatographic electron capture detector was used. The recovery rate of fluoxazole was 0.05-1 in field water and field soil. OOmg/kg fluoxazole standard sample; The average recovery was 78.5% and 101.1%, and the relative standard deviation was 2.0-7.7%, and the average recovery rate was 78.5% -101.1%, and the relative standard deviation was 2.0-7.7%. It meets the technical requirements of pesticide residue analysis and detection. (2) the degradation dynamics and final residues of fluoxazole in paddy field environment were studied. The experimental results show that the first-order kinetic equation (C _ (C) -Coe-kl) can be used to describe the digestion dynamics of fluocyrazole in rice environment. A field trial of fluoxazole was carried out in Changsha and the suburbs of Beijing from 2013 to 2014. The average half-life of fluoxazole in paddy field, soil and rice plant was 3.60 days, 13.38 days and 4.20 days, respectively. Therefore, flucyclazole belongs to easily digestible pesticide (T 1 / 230 d). The results of the final residue test showed that the dose of fluoxazole was 900g / hm ~ (2), the number of times of application was 2 times, and the interval of 28 days after the last application was 28 days. The adsorption equilibrium time of flucyclazole in five different soils was 24 h, and the adsorption principle could be fitted by Freundlich isothermal adsorption equation. The adsorption capacity is: red soil, Shandong cinnamon soil, Heilongjiang black soil, Chongqing purple soil) Hunan river tidal soil. Physical adsorption (AG40 kJ/mol) was observed in the five soils. The adsorption capacity of flucyclazole changed with the change of pH value. When the pH value increased from 7 to 11:00, the adsorption capacity also increased. When the soil temperature was 25 鈩，
本文編號：2373739
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