Influence of soil properties on sorption‐desorption of imidacloprid

Abstract

Sorption‐desorption studies of imidacloprid (1‐[(6‐chloro‐3‐pyridmyl)methyl]‐N‐mtro‐2‐imidazolidinimine) were conducted using the batch equilibration method with seven U.S. soils varying in their physicochemical properties. Initial imidacloprid concentrations ranged from 3 to 300 μg L^‐1. Sorption coefficients K_f and the soil properties organic carbon and CEC gave the higher single correlation coefficients; the latter due to the positive correlation between OC and CEC. Sorption was irreversible and desorption hysteresis in general was greater at low soil solution concentrations. K_f values were lower at 1:5 soil:solution ratio than at 1:1, suggesting a possible effect of a soluble soil component, such as salt concentration, on sorption; no significant differences in pH between solutions were detected.

Key words:

• Sorption
• desorption
• imidacloprid
• soils