title: Influence of complexation phenomena with multivalent cations on the analysis of glyphosate and aminomethyl phosphonic acid in water.
abstract: Experimental and theoretical influence of multivalent cations on the analysis of glyphosate and aminomethyl phosphonic acid (AMPA) was studied in pure water and in one surface water. The procedure chosen, based on derivatization with FMOC-Cl, HPLC separation, and fluorescence detection, appears highly affected at cations concentrations current in natural waters. A detailed speciation study performed with the VMINTEQ software strongly suggests that the complexes formed between analytes and cations do not dissociate during the reaction and do not react with the derivatization agent, so that only the free forms are derivatized. These results point out the necessity of a pre-treatment to prevent these interferences, even in low salinity waters. The different ways conceivable are discussed in terms of kinetic and thermodynamic considerations.
authors.affiliation: Equipe Paysage et Biodiversité, UFR Science, 2 Bd Lavoisier, F-49000 Angers, France. ingrid.freuze@univ-angers.fr
authors.forename: Ingrid
authors.initials: I
authors.lastname: Freuze
authors.forename: Alain
authors.initials: A
authors.lastname: Jadas-Hecart
authors.forename: Alain
authors.initials: A
authors.lastname: Royer
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Communal
mesh_terms: D000327:Adsorption; D002118:Calcium / Q000737:chemistry; D002412:Cations / Q000737:chemistry*; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry; D005449:Fluorenes / Q000737:chemistry; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis; D007501:Iron / Q000737:chemistry; D007555:Isoxazoles; D063065:Organophosphonates / Q000032:analysis*; D013777:Tetrazoles; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015032:Zinc / Q000737:chemistry; D000097797:Glyphosate
chemical_list: D002118:Calcium; D002412:Cations; D003300:Copper; D005449:Fluorenes; D005998:Glycine; D007501:Iron; D007555:Isoxazoles; D063065:Organophosphonates; D013777:Tetrazoles; D014874:Water Pollutants, Chemical; D015032:Zinc; D000097797:Glyphosate; C054007:1-(9-fluorenyl)methyl chloroformate; C418233:2-amino-3-(3-hydrox-5(2-methyl-2H-tetrazol-5-yl)isoxazol-4-yl)propionic acid