Related Experiment Video
Updated: Jun 23, 2026

Measuring Rates of Herbicide Metabolism in Dicot Weeds with an Excised Leaf Assay
Published on: September 7, 2015
Competitive sorption between imidacloprid and imidacloprid-urea on soil clay minerals and humic acids
Weiping Liu1, Wei Zheng, Jianying Gan
1Institute of Environmental Science, Zhejiang University, P.O. Box 1707, Hangzhou 310027, People's Republic of China. wpliu@mail.hz.zj.cn
Abstract:
Soil organic matter and clay minerals are responsible for the adsorption of many pesticides. Adsorption and competitive sorption of imidacloprid on clay minerals and humic acids (HA) were determined using the batch equilibration method. The sorption coefficient of imidacloprid on humic acids was significantly higher than that on Ca-clay minerals, indicating that soil organic matter content was a more important property in influencing the adsorption of imidacloprid. Competitive sorption was investigated between imidacloprid and its main metabolite imidacloprid-urea on HA and Ca-clay minerals. The results showed that the sorption capacity of imidacloprid on clay minerals and HA was reduced in the presence of the metabolite, implying that imidacloprid-urea could occupy or block adsorption sites of imidacloprid on soil, potentially affecting the fate, transport, and bioavailability of imidacloprid in the environment. The interactions between a Ca-clay or HA-clay mixture and adsorption of imidacloprid and imidacloprid-urea were studied using IR differential spectra on thin films made of the adsorbent. The possible mechanisms were discussed from the shift of characteristic IR absorption bands of imidacloprid and imidacloprid-urea after sorption.
Related Concept Videos
Factors Affecting Solubility
Precipitation of Ions
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
Adsorption of Gases on Solids
Adsorption Isotherms I
Microbial Bioremediation of Uranium

