title: Transport and modification of humic substances present in Antarctic snow and ancient ice.
abstract: We performed a study of fulvic acids extracted from fresh and aged snow, and from recent and ancient ice in Antarctica. The fresh snow samples were collected in coastal and inland sites to evaluate the influence of the distance from the sea on organic matter transport. Moreover, in a site (Melbourne Mountain) samples were collected at different heights to study the influence of altitude on transport. The obtained results showed that dissolved fulvic acid concentrations are influenced neither by distance nor by height while particulate fulvic acid concentrations are influenced by both parameters. Moreover, the results showed that fulvic acids transported for a long distance can undergo chemical modifications. Chemical modifications are better evidenced by the analysis of samples taken in trenches at different depth, which showed structural changes attributable to the loss of nitrogen-containing compounds and to an increase in aromatic character of the structures due to reduction and/or condensation processes. With ageing, the humification process proceeds with heavy carbon losses as demonstrated by results obtained from fulvic acids isolated from ice aged between twenty-five thousand and seventy thousand years.
authors.affiliation: Department of Chemistry, University of Rome La Sapienza, P.le Aldo Moro 5, 00185 Roma, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Calace
authors.forename: Enrico
authors.initials: E
authors.lastname: Cantafora
authors.forename: Sabrina
authors.initials: S
authors.lastname: Mirante
authors.forename: Bianca Maria
authors.initials: BM
authors.lastname: Petronio
authors.forename: Marco
authors.initials: M
authors.lastname: Pietroletti
mesh_terms: D000336:Aerosols; D000864:Antarctic Regions; D001578:Benzopyrans / Q000032:analysis; D002244:Carbon / Q000032:analysis; D004784:Environmental Monitoring; D006812:Humic Substances; D007053:Ice / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis; D012623:Seawater; D012914:Snow / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000336:Aerosols; D001578:Benzopyrans; D006812:Humic Substances; D007053:Ice; D002244:Carbon; D009584:Nitrogen; C005023:fulvic acid