title: Improved coupled-column liquid chromatographic method for the determination of glyphosate and aminomethylphosphonic acid residues in environmental waters.
abstract: An existing method for the determination of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) in water has been improved. It is based on precolumn derivatization with the fluorescent reagent 9-fluorenylmethylcloroformate (FMOC) followed by large-volume injection in a coupled-column LC system using fluorescence detection (LC-LC-FD). The derivatization step was slightly modified by changing parameters such as volume and/or concentration of sample and reagents to decrease the limits of quantification (LOQ) of glyphosate and AMPA to 0.1 microg/l. Additionally, the use of Amberlite IRA-900 for preconcentration of glyphosate, prior to the derivatization step, was investigated; the LOQ of glyphosate was lowered to 0.02 microg/l. Drinking, surface and ground water spiked with glyphosate and AMPA at 0.1-10 microg/l concentrations were analysed by the improved LC-LC-FD method. Recoveries were 87-106% with relative standard deviations lower than 8%. Drinking and ground water spiked with glyphosate at 0.02 and 0.1 microg/l were analysed after preconcentration on the anion-exchange resin with satisfactory recoveries (94-105%) and precision (better than 8%).
authors.affiliation: Department of Chemistry, University of Girona, Campus de Montilivi, 17071 Girona, Spain.
authors.forename: Carmén
authors.initials: C
authors.lastname: Hidalgo
authors.forename: Carolina
authors.initials: C
authors.lastname: Rios
authors.forename: Manuela
authors.initials: M
authors.lastname: Hidalgo
authors.forename: Victòria
authors.initials: V
authors.lastname: Salvadó
authors.forename: Juan V
authors.initials: JV
authors.lastname: Sancho
authors.forename: Félix
authors.initials: F
authors.lastname: Hernández
mesh_terms: D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis*; D007555:Isoxazoles; D063065:Organophosphonates / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D013777:Tetrazoles; D014874:Water Pollutants, Chemical / Q000032:analysis*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D007555:Isoxazoles; D063065:Organophosphonates; D013777:Tetrazoles; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C418233:2-amino-3-(3-hydrox-5(2-methyl-2H-tetrazol-5-yl)isoxazol-4-yl)propionic acid