[Study on adsorption of atrazine by soil leaching column chromatography]

A recently developed soil leaching column chromatography was applied to study the adsorption of pesticide in water-soil system. Soil was filled directly into a liquid chromatographic column and pesticide solution was applied as an eluant, and the adsorption equilibrium was monitored by a UV detector. The herbicide atrazine, i. e. 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, was chosen as an example. Its mass concentration ranged from 19.73 mg/L to 29.60 g/L. After the soil phase was rinsed with methanol, the amount of atrazine adsorbed was calculated from the difference between the atrazine totally rinsed and that in solution in the column. The low content atrazine sample was determined by enrichment on an ODS column and step-gradient method. It shows that the adsorption of atrazine on a sandy loam soil is in accordance with Freundlich isotherm. The adsorption coefficient Kf is 842.6 mL/kg and the normalized organic carbon adsorption coefficient log Koc is 1.832.