title: Use of liquid chromatography/electrospray ionization tandem mass spectrometry to study the degradation pathways of terbuthylazine (TER) by Typha latifolia in constructed wetlands: identification of a new TER metabolite.
abstract: S-Triazines are used worldwide as herbicides for agricultural and non-agricultural purposes. Although terbuthylazine (TER) is the second most frequently used S-triazine, there is limited information on its metabolism. For this reason, an analytical method based on liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) has been developed aiming at the identification of TER and its five major metabolites (desisopropyl-hydroxy-atrazine, desethyl-hydroxy-terbuthylazine, desisopropyl-atrazine, hydroxy-terbuthylazine and desethyl-terbuthylazine) in constructed wetland water samples. The separation of TER and its major metabolites was performed by reversed-phase high-performance liquid chromatography (HPLC) on a C(8) column using a gradient elution of aqueous acetic acid 1% (solvent A) and acetonitrile (solvent B), followed by MS/MS analysis on a triple quadrupole mass spectrometer. The data-depended analysis (DDA) scan approach has been employed and the main degradation pathways of both hydroxyl and chloro (dealkylated and alkylated) metabolites are elucidated through the tandem mass spectral (MS/MS) interpretation of triazine fragments under CID conditions. In addition, another major metabolite of TER, namely N2-tert-butyl-N4-ethyl-6-methoxy-1,3,5-triazine-2,4-diamine, has been identified. This methodology can be further employed in biodegradation studies of TER, thus assisting the assessment of its environmental impact.
authors.affiliation: Bioanalytical Laboratory, GAIA Research Center, The Goulandris Natural History Museum, 13 Levidou str., 145 62 Kifissia, Greece.
authors.forename: Evagelos
authors.initials: E
authors.lastname: Gikas
authors.forename: Nikolaos G
authors.initials: NG
authors.lastname: Papadopoulos
authors.forename: Fotini N
authors.initials: FN
authors.lastname: Bazoti
authors.forename: Georgios
authors.initials: G
authors.lastname: Zalidis
authors.forename: Anthony
authors.initials: A
authors.lastname: Tsarbopoulos
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004785:Environmental Pollutants / Q000737:chemistry / Q000378:metabolism; D006540:Herbicides / Q000737:chemistry* / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014227:Triazines / Q000737:chemistry* / Q000378:metabolism*; D032401:Typhaceae / Q000378:metabolism*; D053833:Wetlands
chemical_list: D004785:Environmental Pollutants; D006540:Herbicides; D014227:Triazines; C037565:terbutylazine