title: Study of the photochemical transformation of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA) under conditions relevant to surface waters.
abstract: We studied the aquatic environmental fate of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA), a widespread sunscreen, to assess its environmental persistence and photoinduced transformation. Direct photolysis is shown to play a key role in phototransformation, and this fast process is expected to be the main attenuation route of OD-PABA in sunlit surface waters. The generation of transformation products (TPs) was followed via HPLC/HRMS. Five (or four) TPs were detected in the samples exposed to UVB (or UVA) radiation, respectively. The main detected TPs of OD-PABA, at least as far as HPLC-HRMS peak areas are concerned, would involve a dealkylation or hydroxylation/oxidation process in both direct photolysis and indirect phototransformation. The latter was simulated by using TiO2-based heterogeneous photocatalysis, involving the formation of nine additional TPs. Most of them resulted from the further degradation of the primary TPs that can also be formed by direct photolysis. Therefore, these secondary TPs might also occur as later transformation intermediates in natural aquatic systems.
authors.affiliation: Department of Chemistry, University of Torino, Via P. Giuria 5, 10125, Torino, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Calza
authors.affiliation: Department of Chemistry, University of Torino, Via P. Giuria 5, 10125, Torino, Italy; NatRisk Inter-Department Centre, University of Torino, Via L. da Vinci 44, 10095, Grugliasco (TO), Italy. Electronic address: davide.vione@unito.it.
authors.forename: D
authors.initials: D
authors.lastname: Vione
authors.affiliation: Department of Chemistry, University of Torino, Via P. Giuria 5, 10125, Torino, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Galli
authors.affiliation: Department of Chemistry, University of Torino, Via P. Giuria 5, 10125, Torino, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Fabbri
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Via P. Giuria 5, 10125, Torino, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Dal Bello
authors.affiliation: Department of Molecular Biotechnology and Health Sciences, University of Torino, Via P. Giuria 5, 10125, Torino, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Medana
mesh_terms: D002384:Catalysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004777:Environment; D017665:Hydroxyl Radical; D055668:Photochemical Processes; D010782:Photolysis; D013473:Sunscreening Agents / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D062366:para-Aminobenzoates / Q000737:chemistry*
chemical_list: D013473:Sunscreening Agents; D014874:Water Pollutants, Chemical; D062366:para-Aminobenzoates; D014867:Water; C009495:titanium dioxide; D017665:Hydroxyl Radical; D014025:Titanium; C041981:padimate-O
keywords: OD-PABA; Photolysis; Sunscreen; Titanium dioxide; Transformation products