Desorption of Atrazine and Cyanazine from Soil

Document Type

Article

Publication Date

1988

Abstract

Removal of soluble soil organic carbon (SSOC) during herbicide desorption studies using the batch equilibration method may affect the herbicide-soil-solution equilibrium particularly if herbicide-SSOC complexes can form. Desorption characteristics of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and cyanazine (2-{[4-chloro-6-(ethylamino)-s-triazine-2-yl]amino}-2-methylpropionitrile] were determined in a Ves clay loam (Aquic Hapludolls). For adsorption, the soil was equilibrated with 0.01 M CaCl2 solutions containing atrazine or cyanazine. Desorption with 0.01 M CaCl2 each day for 5 d resulted in hysteresis when compared to the adsorption isotherm. Replacement of the equilibration solution with soil extract for 5 d, while maintaining a higher SSOC content in the desorption equilibration solution than did the CaCl2 solution, did not change desorption isotherm equations. The SSOC-herbicide complexes were not detected in any of the adsorption and desorption equilibration solutions by ultrafiltration (membranes with molecular mass cut offs of 10 000 and 500 daltons), HPLC, or TLC techniques. Either s-triazine-SSOC complexes were not formed in sufficient quantities or they were not stable enough to affect desorption of the herbicide during batch equilibration.

Publication Title

Journal of Environmental Quality

Volume

17

Issue

4

First Page

719

Last Page

723

DOI of Published Version

10.2134/jeq1988.00472425001700040034x

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