title: Photoenhanced transformation of nicotine in aquatic environments: involvement of naturally occurring radical sources.
abstract: This work investigated the fate of nicotine (Nico) in aqueous solution upon reaction with singlet oxygen ((1)O2) and hydroxyl radical (HO·). The second-order rate constants of Nico with (1)O2 (k(Nico,(1)O(2)) = (3.38 ± 0.14) × 10(6) M(-1) s(-1)) and HO· (kNico,·OH = (1.08 ± 0.10) × 10(9) M(-1) s(-1)) were determined using competition kinetics. Photochemical modelling showed that the reaction of Nico with HO· would prevail over that with (1)O2 in surface waters transformation pathway. The Nico photochemical half-life time could be accounted for by the two reactions. This value would vary in the month-year range depending on the environmental conditions: phototransformation would be favoured in shallow water poor in organic matter and rich in nitrate and nitrite. Irradiation experiments of Nico with nitrite suggested that transformation could not be accounted for by HO· reaction alone. Indeed, a variable fraction of Nico transformation (30-80% depending on the conditions) would take place upon reaction with additional transients, photogenerated NOx being possible candidates. The chemical structures of the transformation intermediates were derived by means of HPLC-MS. The detection of nitroderivatives upon irradiation of Nico with nitrite suggests the involvement of nitrogen dioxide in the relevant photoprocesses.
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand (ICCF) - ENSCCF, BP 10448, F-63000 Clermont-Ferrand, France; CNRS, UMR 6296, ICCF, F-63171 Aubière, France; UdR Napoli 4 INCA Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Passananti
authors.affiliation: UdR Napoli 4 INCA Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Temussi
authors.affiliation: UdR Napoli 4 INCA Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Iesce
authors.affiliation: UdR Napoli 4 INCA Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy.
authors.forename: Lucio
authors.initials: L
authors.lastname: Previtera
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand (ICCF) - ENSCCF, BP 10448, F-63000 Clermont-Ferrand, France; CNRS, UMR 6296, ICCF, F-63171 Aubière, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Mailhot
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy(1); Università degli Studi di Torino, Centro Interdipartimentale NatRisk, Via L. Da Vinci 44, 10095 Grugliasco, TO, Italy(2).
authors.forename: Davide
authors.initials: D
authors.lastname: Vione
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand (ICCF) - ENSCCF, BP 10448, F-63000 Clermont-Ferrand, France; CNRS, UMR 6296, ICCF, F-63171 Aubière, France. Electronic address: marcello.brigante@univ-bpclermont.fr.
authors.forename: Marcello
authors.initials: M
authors.lastname: Brigante
mesh_terms: D002851:Chromatography, High Pressure Liquid; D017665:Hydroxyl Radical / Q000737:chemistry*; D009538:Nicotine / Q000737:chemistry*; D010777:Photochemistry
chemical_list: D017665:Hydroxyl Radical; D009538:Nicotine
keywords: Environmental fate; Hydroxyl radical; Modelled half-life time; Nitrogen-centred radicals; Surface water