Dipartimento di Agraria, Desertification Research Group (NRD), Università di Sassari, Viale Italia 39, 07100 Sassari, Italy.
Chemosphere. 2013 Apr;91(3):265-8. doi: 10.1016/j.chemosphere.2012.11.023. Epub 2012 Dec 6.
The sorption of meta and para isomers of the herbicide imazamethabenz-methyl, methyl 6-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-m- or p-toluate, by three soils and soil organic matter, was studied. Sorption isotherms conformed to the Freundlich equation. It was found that pH was the main factor influencing the adsorption in all of the systems. The highest level of sorption was measured on soils with low pH and high organic carbon content. Moreover, at low pH value, the soil rich in smectite clays, favoured the sorption of meta rather than para isomer. The higher affinity of clay surfaces for the meta isomer of the herbicide is due to the stabilization of the meta protonated form by resonance. At all pH values, the sorption on soil organic matter did not differ between two isomers.
研究了除草剂咪草烟甲酯，即 6-[(RS)-4-异丙基-4-甲基-5-氧代-2-咪唑啉-2-基]-m-或 p-甲苯酸甲酯的间位和对位异构体，在 3 种土壤和土壤有机质中的吸附情况。吸附等温线符合弗伦德利希方程。结果表明，pH 是所有体系中影响吸附的主要因素。在 pH 值较低且有机碳含量较高的土壤中，吸附量最大。此外，在低 pH 值下，富含蒙脱石黏土的土壤有利于间位异构体的吸附而不是对位异构体。粘土表面对除草剂间位异构体的高亲和力是由于共振稳定了间位质子化形式。在所有 pH 值下，两种异构体在土壤有机质上的吸附没有差异。
