Sorption of Two New Sulfonylaminocarbonyltriazolinone Herbicides and their Metabolites on Organic and Inorganic Exchanged Smectites

The sorption capacity and possible mechanisms of sorption of two new sulfonylaminocarbonyltriazolinone herbicides, methyl 2-[[[(4,5-dihydro-4-methyl-5-oxo-3-propoxy-1 H -1,2,4-triazol-1-yl)carbonyl]amino]sulfonyl]benzoate (MKH 6561) and (4,5-dihydro-3-methoxy-4-methyl-5-oxo- N -[[2-(trifluoromethoxy)phenyl]sulfonyl]-1 H -1,2,4-triazole-1-carboxamide) (MKH 6562), and their potential metabolites, 2,4-dihydro-4-methyl-5-propoxy-3 H -1,2,4-triazol-3-one (triazole) and 2-trifluoromethoxybenzenesulfonamide (phenylsulfonamide) on octadecyl (C18) and dioctadecyldimethylammonium (DOD) saturated and Fe 3+ and Na + saturated smectites has been investigated. Sorption of MKH 6561 on inorganic clays and C18 organoclays was much higher than for MKH 6562, but was similar on DOD saturated clays. For C18 saturated clays, sorption of both parent compounds increased with decreasing layer charge of the organosmectite. Sorption of triazole metabolite, which was much lower than for its parent compound MKH 6561, was higher on inorganic and C18 saturated clays than on DOD saturated clays or inorganic clays. Phenylsulfonamide metabolic sorption, which was also lower than the corresponding parent compound MKH 6562, was higher on DOD saturated clays than on C18 or inorganic saturated clays. These differences in sorption behaviour are related to the diverse relative contribution of hydrophobic and polar interactions for the various compound-clay systems.

Keywords:

• Alkylammonium Cations
• Clay
• Metabolites
• Organoclay
• Smectite
• Sorption
• Sulfonylaminocarbonyltriazolinone Herbicides