title: Interaction of pyrene fluoroprobe with natural and synthetic humic substances: Examining the local molecular organization from photophysical and interfacial processes.
abstract: The direct and indirect interaction mechanisms of pyrene with: (i) various molecular weight fractions of a synthetic humic-like substance (SyHA) and (ii) extracts of natural humic acids (NHA) from Moselle River suspended matter were investigated using quenching fluorescence and surface tension measurements. Humic materials were characterized in a previous study. The Stern-Volmer associative constants were determined from the quenching technique. Surface tension measurements revealed an increase in surface activity as a function of concentration for each humic fraction independently of the pyrene presence in solution, even during the formation of humic micelles. The results obtained suggest the possibility of specific intermolecular interactions occurring during pyrene entrapment within humic acids. In addition, we show that molecular weight, aliphatic chains (especially those containing nitrogen groups) and number of acidic groups are determinant characteristics for pollutant entrapment capacity at concentrations below the critical micellar concentration (CMC) of humic substances.
authors.affiliation: Ecole des Métiers de l'Environnement, Campus de Ker Lann, Avenue Schuman, Bruz, France. av2jung@live.fr
authors.forename: A-V
authors.initials: AV
authors.lastname: Jung
authors.forename: C
authors.initials: C
authors.lastname: Frochot
authors.forename: F
authors.initials: F
authors.lastname: Villieras
authors.forename: B S
authors.initials: BS
authors.lastname: Lartiges
authors.forename: S
authors.initials: S
authors.lastname: Parant
authors.forename: M-L
authors.initials: ML
authors.lastname: Viriot
authors.forename: J-L
authors.initials: JL
authors.lastname: Bersillon
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005456:Fluorescent Dyes; D005602:France; D019015:Geologic Sediments / Q000737:chemistry; D006812:Humic Substances / Q000032:analysis*; D008970:Molecular Weight; D011721:Pyrenes / Q000032:analysis* / Q000737:chemistry; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D006812:Humic Substances; D011721:Pyrenes; D012996:Solutions; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C030984:pyrene