Reversed‐phase chromatographic study of the binding of pesticides to humus extract

The interaction of 18 pesticides with humus extract was studied by reversed‐phase thin‐layer chromatography and the effect of pH and the concentration of sodium chloride on the interaction was assessed. Interaction of six pesticides with humus extract was confirmed in an aqueous system; the strength of interaction was highly dependent on the chemical structure of the pesticides. No significant interaction was detected under acidic or alkaline conditions. Sodium chloride markedly decreased the strength of interaction, indicating the hydrophilic character of the interactive forces. © 2000 Society of Chemical Industry