Accueil > Résultats de la recherche > Suite de la publication

Photochemically-Induced Fluorescence (PIF)and UV-vis Absorption Determination ofDiuron and Metalaxyl in Well Water, Kinetic ofPhotodegradation and Rate of Leach Ability inSoils

Aromatic pesticides are toxic substances for the environment and humans. In this study, thephotodegradation kinetics, the rate of leach ability in soils and the analytical determination of diuron andmetalaxyl residues in well water by liquid-liquid extraction procedure have been determined by UV-visibleabsorption and photochemically-induced fluorescence (PIF). We studied the photodegradation kinetics byUV-visible absorption spectroscopy and a second-order kinetics with lifetime values of 6.0 and 0.5 hours wasfound in water for metalaxyl and diuron, respectively. Physicochemical parameters affecting the sensitivity ofthe PIF method, such as solvent, pH and UV irradiation time were investigated. PIF method was then per-formed in optimal analytical conditions. The limits of detection (LOD) ranging from 3.2 to 14 ng mL-1 wereparticularly low and the small relative standard deviation (RSD) (< 4 %), indicated a very good analyticalsensitivity and a great repeatability of PIF method. Then, an investigation the pesticides leach ability wasconducted in agricultural soil. We obtained rates of infiltration of 12.7 mm/min for diuron and 1.6 mm/min formetalaxyl. These results showed that both pesticides have high groundwater pollution potential. Finally, ap-plication to the analysis of these pesticides in spiked well water samples yielded satisfactory recovery values(87-108 %).

Auteur(s) : Med Lemine Ould Cheikh Ould Saleck, Diène Diégane Thiaré, SouleymaneSambou, El Hadji Tombé Bodian, Ibrahima Sarr, Diégane Sarr, Cheikh Diop,Mame Diabo
Pages : 806-815
Année de publication : 2019
Revue : Analytical Chemistry Letters
N° de volume : 9
Type : Article
Mise en ligne par : FALL Modou