title: A simple and green analytical method for determination of glyphosate in commercial formulations and water by diffuse reflectance spectroscopy.
abstract: This article describes a simple, inexpensive, and environmentally friendly method for the monitoring of glyphosate using diffuse reflectance spectroscopy. The proposed method is based on reflectance measurements of the colored compound produced from the spot test reaction between glyphosate and p-dimethylaminocinnamaldehyde (p-DAC) in acid medium, using a filter paper as solid support. Experimental designs were used to optimize the analytical conditions. All reflectance measurements were carried out at 495 nm. Under optimal conditions, the glyphosate calibration graphs obtained by plotting the optical density of the reflectance signal (AR) against the concentration were linear in the range 50-500 μg mL(-1), with a correlation coefficient of 0.9987. The limit of detection (LOD) for glyphosate was 7.28 μg mL(-1). The technique was successfully applied to the direct determination of glyphosate in commercial formulations, as well as in water samples (river water, pure water and mineral drinking water) after a previous clean-up or pre-concentration step. Recoveries were in the ranges 93.2-102.6% and 91.3-102.9% for the commercial formulations and water samples, respectively.
authors.affiliation: Instituto de Química-UNESP-University Estadual Paulista, PO Box 355, CEP 14801-970 Araraquara, SP, Brazil.
authors.forename: Aline Santana
authors.initials: AS
authors.lastname: da Silva
authors.forename: Flávio Cesar Bedatty
authors.initials: FC
authors.lastname: Fernandes
authors.forename: João Olímpio
authors.initials: JO
authors.lastname: Tognolli
authors.forename: Leonardo
authors.initials: L
authors.lastname: Pezza
authors.forename: Helena Redigolo
authors.initials: HR
authors.lastname: Pezza
mesh_terms: D002138:Calibration; D004058:Diffusion; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis; D055772:Green Chemistry Technology; D045483:Rivers / Q000737:chemistry; D014867:Water / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D014867:Water; D014874:Water Pollutants, Chemical; D000097797:Glyphosate