title: Sulfosulfuron incorporated in micelles adsorbed on montmorillonite for slow release formulations.
abstract: Slow release formulations of the anionic herbicide sulfosulfuron (SFS) were prepared by incorporating it in micelles of an organic cation octadecyltrimethylammonium, which adsorb on the clay-mineral montmorillonite. The fraction of SFS adsorbed on the micelle-clay complex reached 98%, whereas for monomer-clay complexes, its adsorption was insignificant. Fluorescence studies showed surface contact between the micelles and the clay surface. The rate of SFS release from the micelle-clay formulations in aqueous suspensions was slow (<1%, 72 h). Spraying SFS formulations on a thin soil layer in a funnel, followed by irrigations (50 mm), resulted in complete elution of SFS from the commercial formulation (dispersible granular) versus 4% from the micelle-clay formulation. A plant bioassay in Rehovot soil showed that these respective formulations yielded 23 and 65% of shoot growth inhibition of foxtail. Consequently, the slow release micelle-clay formulations of SFS yield significantly reduced leaching and enhanced biological activity, thus providing environmental and agricultural advantages.
authors.affiliation: Seagram Center for Soil and Water Sciences, Faculty of Agricultural, Food, and Environmental Sciences, Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Yael G
authors.initials: YG
authors.lastname: Mishael
authors.forename: Tomas
authors.initials: T
authors.lastname: Undabeytia
authors.forename: Onn
authors.initials: O
authors.lastname: Rabinovitz
authors.forename: Baruch
authors.initials: B
authors.lastname: Rubin
authors.forename: Shlomo
authors.initials: S
authors.lastname: Nir
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003692:Delayed-Action Preparations; D006540:Herbicides / Q000008:administration & dosage / Q000737:chemistry*; D008823:Micelles; D011743:Pyrimidines / Q000008:administration & dosage / Q000737:chemistry*; D013449:Sulfonamides / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D006540:Herbicides; D008823:Micelles; D011743:Pyrimidines; D013449:Sulfonamides; D001546:Bentonite; C439268:sulfosulfuron