title: Assessing the photochemical transformation pathways of acetaminophen relevant to surface waters: transformation kinetics, intermediates, and modelling.
abstract: This work shows that the main photochemical pathways of acetaminophen (APAP) transformation in surface waters would be direct photolysis (with quantum yield of (4.57 ± 0.17)⋅10(-2)), reaction with CO3(-·) (most significant at pH > 7, with second-order rate constant of (3.8 ± 1.1)⋅10(8) M(-1) s(-1)) and possibly, for dissolved organic carbon higher than 5 mg C L(-1), reaction with the triplet states of chromophoric dissolved organic matter ((3)CDOM*). The modelled photochemical half-life time of APAP in environmental waters would range from days to few weeks in summertime, which suggests that the importance of phototransformation might be comparable to biodegradation. APAP transformation by the main photochemical pathways yields hydroxylated derivatives, ring-opening compounds as well as dimers and trimers (at elevated concentration levels). In the case of (3)CDOM* (for which the triplet state of anthraquinone-2-sulphonate was used as proxy), ring rearrangement is also hypothesised. Photochemistry would produce different transformation products (TPs) of APAP than microbial biodegradation or human metabolism, thus the relevant TPs might be used as markers of APAP photochemical reaction pathways in environmental waters.
authors: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy.
authors: Elisa
authors: E
authors: De Laurentiis
authors: Federal Institute of Hydrology (BfG), Referat G2, Am Mainzer Tor 1, 56068 Koblenz, Germany.
authors: Carsten
authors: C
authors: Prasse
authors: Federal Institute of Hydrology (BfG), Referat G2, Am Mainzer Tor 1, 56068 Koblenz, Germany.
authors: Thomas A
authors: TA
authors: Ternes
authors: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy.
authors: Marco
authors: M
authors: Minella
authors: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy.
authors: Valter
authors: V
authors: Maurino
authors: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy.
authors: Claudio
authors: C
authors: Minero
authors: Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France; CNRS, UMR 6296, ICCF, BP 80026, F-63177 Aubière, France.
authors: Mohamed
authors: M
authors: Sarakha
authors: Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France; CNRS, UMR 6296, ICCF, BP 80026, F-63177 Aubière, France.
authors: Marcello
authors: M
authors: Brigante
authors: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy; Università degli Studi di Torino, Centro Interdipartimentale NatRisk, Via L. Da Vinci 44, 10095 Grugliasco, TO, Italy. Electronic address: davide.vione@unito.it.
authors: Davide
authors: D
authors: Vione
mesh_terms: D000082:Acetaminophen / Q000737:chemistry*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry; D006207:Half-Life; D007700:Kinetics; D008956:Models, Chemical; D055668:Photochemical Processes; D010782:Photolysis; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D000082:Acetaminophen
keywords: Acetaminophen; Acetyl-para-aminophenol; Direct and sensitised photolysis; Paracetamol; Pharmaceuticals and personal care products (PPCPs); Surface-water photochemistry