title: Identification of oxidative coupling products of xylenols arising from laboratory-scale phytoremediation.
abstract: Oxidative coupling reactions take place during the passage of xylenols through a laboratory-scale helophyte-based constructed wetland system. Typical coupling product groups including tetramethyl-[1,1'-biphenyl] diols and tetramethyl diphenylether monools as stable organic intermediates could be identified by a combination of pre-chromatographic derivatization and GC/MS analysis. Structural assignment of individual analytes was performed by an increment system developed by Zenkevich to pre-calculate retention sequences. The most abundant analyte turned out to be 3,3',5,5'-tetramethyl-[1,1'-biphenyl]-4,4'-diol, which can be formed by a combination of radicals based on 2,6-xylenol or by an attack of a 2,6-xylenol-based radical on 2,6-xylenol. Organic intermediates originating from oxidative coupling could also be identified in anaerobic constructed wetland systems. This finding suggested the presence of (at least partly) oxic conditions in the rhizosphere.
authors.affiliation: UFZ-Helmholtz Center for Environmental Research, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany. Electronic address: juergen.poerschmann@ufz.de.
authors.forename: J
authors.initials: J
authors.lastname: Poerschmann
authors.affiliation: UFZ-Helmholtz Center for Environmental Research, Department of Environmental Biotechnology, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Schultze-Nobre
authors.affiliation: UFZ-Helmholtz Center for Environmental Research, Department of Ecological Chemistry, Germany.
authors.forename: R U
authors.initials: RU
authors.lastname: Ebert
authors.affiliation: University of Waterloo, Department of Chemistry, Waterloo, ON N2L 3G1, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Górecki
mesh_terms: D001673:Biodegradation, Environmental; D008401:Gas Chromatography-Mass Spectrometry; D019684:Magnoliopsida / Q000378:metabolism*; D058451:Oxidative Coupling; D058441:Rhizosphere; D053833:Wetlands; D014992:Xylenes / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D014992:Xylenes; C036531:2,6-xylenol; C016834:3,5-xylenol
keywords: Biphenyl-type coupling products; Constructed wetlands; Oxidative coupling reactions; Retention index increment approach; Xylenols