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采用室内砂柱模拟试验方法研究了红壤和黑土两种土壤胶体对草萘胺在砂质土柱中迁移的影响.结果表明,整个淋滤过程中红壤和黑土胶体的回收率比较高,分别达到66.76%和74.75%;胶体促进了草萘胺在砂质土柱中的迁移,与对照相比(无胶体),加入红壤和黑土胶体后草萘胺的回收率分别提高了9.82%和10.63%.但是吸附在胶体上迁移的草萘胺数量比较少,只占到迁移总量的1.15%(红壤)和1.68%(黑土),物理非平衡机制可能在迁移过程中起支配作用. 相似文献
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In laboratory incubations, the times to 50% loss (DT50) of a first application of napropamide were approximately 25, 45 and 75 days in soil incubated at 25, 15 and 5°C respectively. When treated for a second time, the DT50 values were 4, 7 and 15 days at the same temperatures, irrespective of the temperature of the first incubation. This indicates that enhanced degradation of napropamide in soil can be both induced and expressed at low temperature. A mixed microbial culture able to degrade the herbicide to a single degradation product, identified by HPLC retention time as naphthoxypropionic acid, was obtained from a soil capable of rapid degradation. Addition of a sub-sample of this mixed culture to a previously untreated soil introduced rapid degrading ability. When small amounts of soil capable of rapid degradation were added to previously untreated soil, in both the laboratory and the field, the degradation rate of napropamide increased compared with that in unamended soils. 相似文献
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The main photoproducts formed in an aqueous solution of napropamide irradiated in UV light are N,N-diethyl-2-(1-hydroxynaphthalen-2-yl)propionamide, N,N-diethyl-2-(4-hydroxynaphthalen-1-yl)propionamide and 1-naphthol. These account for c.60%, 15% and 10% of napropamide converted respectively. No influence of the irradiation wavelength or of oxygen was observed. The same products were obtained by irradiation of methanolic solutions. The three identified products result from the cleavage of naphthoxy–carbon bond. The first two products imply a photo-Fries rearrangement. The influence of irradiation on the toxicity of the solutions was studied by the Microtox™ test. The significant increase observed may be attributed partly to the formation of 1-naphthol. © 1998 Society of Chemical Industry 相似文献
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采用生物培养方法,研究了绿肥、猪粪及污泥中的水溶性有机物(DOM)对土壤中草萘胺生态毒性的影响。结果表明,土壤中草萘胺浓度5～60mg·kg-1与植物种子的发芽指数呈显著负相关性r=-0.9519,与根长抑制率呈显著正相关性r=0.9848;不同来源的DOM均会降低草萘胺的生态毒性,影响程度为猪粪>污泥>绿肥;植物根伸长抑制率与DOM浓度有显著的负相关性r绿肥=-0.9633,r猪粪=-0.8933,r污泥=-0.8509。 相似文献
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利用直链淀粉三-(3,5-二甲基苯基氨基甲酸酯)手性固定相(AD-RH柱)和纤维素三-(3,5-二甲基苯基氨基甲酸酯)手性固定相(OD-RH柱),以乙腈-水为流动相,对敌草胺对映体进行了直接手性拆分研究。考察了流动相组成、流速、柱温等对敌草胺对映体的色谱保留和分离的影响,并对敌草胺对映体与固定相之间的色谱保留和分离的热力学机理进行了讨论。结果表明,在流速为0.5mL/m in、乙腈-水为50∶50(体积比)、柱温在1035℃条件下,AD-RH和OD-RH柱的△△H0值分别为-1 160.79和-673.40J/mol,即AD-RH柱的拆分能力优于OD-RH柱,二者都能实现基线分离。 相似文献
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烟叶中敌草胺残留的分子印迹SPE-HPLC检测 总被引：2，自引：1，他引：1
为了对烟草中敌草胺残留进行高效的富集纯化和测定,建立了敌草胺分子印迹固相萃取-高效液相色谱法进行检测。首先,以敌草胺为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,在液相色谱柱管中70℃聚合24 h,制备对敌草胺具有亲和识别功能的分子印迹原位整体柱,并对其亲和能力进行了表征。然后,用该整体柱萃取富集烟草样品的乙腈提取液,再用反相高效液相色谱测定,结果表明,敌草胺的回收率在(92.3±2.1)%,相对标准偏差在2.76%,检出限1.0 ng/g。可以看出,敌草胺分子印迹原位整体柱是一种有高专属亲和力的固相萃取材料,适合对复杂样品中微量敌草胺的富集纯化,所建立的敌草胺分子印迹SPE-HPLC方法适用于烟叶中敌草胺残留的分析。 相似文献
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敌草胺在土壤中的吸附及其与持久性和生物有效性之间的关系 总被引：1，自引：0，他引：1
土壤吸附是农药在环境中归趋的关键支配因素,也是支配农药在环境中的持久性和生物有效性的重要因素之一。该文采用高效液相色谱法研究了除草剂敌草胺在不同性质土壤中的吸附、持久性和生物有效性以及吸附与土壤持久性、蚯蚓生物有效性之间的关系。结果表明,在供试浓度范围内,采用批量平衡技术测定的敌草胺土壤吸附等温线可用Freundlich模型表征（r>0.99）,土壤有机质含量（PPt50）在61.3-97.6 d之间;微生物对敌草胺在土壤中的持久性影响显著,微生物降解是敌草胺在土壤环境中降解的主要途径,灭菌处理后其在土壤中的半衰期延长了2.09~3.65倍。蚯蚓Eisenia foetida对敌草胺的吸收和生物积累也主要取决于土壤性质,特别是土壤的有机质含量水平（Pr=-0.885,Pr=-0.796,Pt50=94.210-3.535 Kf和BAF=0.264-0.014 Kf,表明吸附系数可用作模型参数来评价敌草胺在土壤中的持久性和生物有效性。 相似文献
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Salinas-Castillo A Fernández-Sanchez JF Segura-Carretero A Fernández-Gutiérrez A 《Pest management science》2005,61(8):816-820
A new, simple, rapid and selective phosphorimetric method for determining napropamide is proposed which demonstrates the applicability of heavy-atom-induced room-temperature phosphorescence for analyzing pesticides in real samples. The phosphorescence signals are a consequence of intermolecular protection and are found exclusively with analytes in the presence of heavy atom salts. Sodium sulfite was used as an oxygen scavenger to minimize room-temperature phosphorescence quenching. The determination was performed in 1 M potassium iodide and 6 mM sodium sulfite at 20 degrees C. The phosphorescence intensity was measured at 520 nm with excitation at 290 nm. Phosphorescence was easily developed, with a linear relation to concentration between 3.2 and 600.0 ng ml(-1) and a detection limit of 3.2 ng ml(-1). The method has been successfully applied to the analysis of napropamide in water and soil samples and an exhaustive interference study was also carried out to display the selectivity of the proposed method. 相似文献
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