title: Conductive-diamond electrochemical oxidation of chlorpyrifos in wastewater and identification of its main degradation products by LC-TOFMS.
abstract: The electrochemical transformation of the organophosphorous insecticide chlorpyrifos (CPF) was investigated in wastewater. The oxidation of CPF was carried out in a single-compartment electrochemical flow cell working under batch operation mode, using diamond-based material as anode and stainless steel as cathode. In order to evaluate its persistence and degradation pathway, two different concentration levels (1.0 mg L(-1) and 0.1 mg L(-1)) were studied. Liquid chromatography/mass spectrometry was used for evaluation of the initial and electrolyzed solutions. The identification of CPF transformation products was performed by liquid chromatography-time of flight-mass spectrometry (LC-TOFMS). Results showed that CPF is completely removed at the end of treatment time. Analysis by LC-TOFMS allowed the identification of six degradation products (with Mw 154, 170, 197, 305 321 and 333). Three of the identified intermediates (Mw 170, 305 and 321) were completely removed at the end of electrolysis time. Interestingly, the formation of diethyl 3,5,6-trichloropyridin-2yl phosphate (chlorpyrifos oxon) and 3,5,6-trichloropyridin-2-ol was also found in previous reported degradation pathways using different degradation technologies.
authors.affiliation: Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Robles-Molina
authors.forename: María J
authors.initials: MJ
authors.lastname: Martín de Vidales
authors.forename: Juan F
authors.initials: JF
authors.lastname: García-Reyes
authors.forename: Pablo
authors.initials: P
authors.lastname: Cañizares
authors.forename: Cristina
authors.initials: C
authors.lastname: Sáez
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Rodrigo
authors.forename: Antonio
authors.initials: A
authors.lastname: Molina-Díaz
mesh_terms: D004390:Chlorpyrifos / Q000032:analysis / Q000737:chemistry*; D002853:Chromatography, Liquid; D018130:Diamond / Q000737:chemistry; D004566:Electrodes; D007306:Insecticides / Q000032:analysis / Q000737:chemistry*; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D004390:Chlorpyrifos; D018130:Diamond; D007306:Insecticides; D062065:Wastewater; D014874:Water Pollutants, Chemical