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EESS talk on "Dissolved organic matter (DOM) composition: recent advances on its molecular and isotopic characterization"

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Event details

Date and time 12.11.2019 12:1513:00  
Place and room
Speaker Dr Christos Panagiotopoulos,Institut Méditerranéen d'Océanologie, Aix-Marseille University (AMU), Marseille (FR) - obtained his Ph. D degree in Chemical Oceanography in Aix Marseille University at 2002 followed by a first post-doc  in Woods Hole Oceanographic Institution (WHOI scholarship; 2003-2005) and a second in Univ. of California (Irvine, fellowship 2005-2006). Since 2006 his holds a researcher CNRS position at the Mediterranean Institute of Oceanography (MIO; https://www.mio.osupytheas.fr). C. Panagiotopoulos is currently head scientist of the chemistry team of MIO (2017- ) and the chemistry facility at the MIO. Research Interests:
-Molecular characterization of dissolved organic matter (DOM) using 1H, 13C,15N NMR, MS, and HPLC techniques.
-Radiocarbon of natural compounds (monosaccharides and amino acids) isolated from DOM.
-Carbohydrate and amino acid geochemistry.
-Organic matter production degradation by bacteria in water column. DOM/POM transformations and distribution in marine waters
-Terrestrial organic matter fluxes in the surface sea and the water column
-DOM monitoring using surface enhanced Raman spectroscopy (SERS).
-Distribution and fluxes of organic contaminants in coastal areas (phthalates, BPA, flame retardants, and pesticides)
-Chemical composition and fluxes of organic compounds (dicarboxylic acids and burning biomass tracers) of atmospheric aerosols into the sea.
Category Conferences - Seminars
Abstract:
Containing as much carbon as the atmosphere, marine dissolved organic matter (DOM) at 662 Pg C is one of Earth’s major carbon reservoirs, holding greater than 200 times the carbon inventory of marine biomass. Marine DOM serves as a substrate to vast heterotrophic microbial population being an important source of C, N, P and is mostly produced autochthonously by photosynthetic plankton in the upper ocean. Despite its large inventory DOM exists in extremely low concentrations (surface/deep: 34-80 µMC), exhibits an old radiocarbon signature (surface/deep: 3000-6000 yr) while only 5-10% is chemically characterized indicating that the fate, the composition and overall the dynamics of DOM are poorly understood. In this talk I will first review previous knowledge gained over the last 3 decades on DOM composition emphasizing in sampling approaches, NMR, mass spectrometry techniques and bulk/molecular level radiocarbon analyses. Then, I will present some of the major achievements on DOM research including data obtained in my lab over the last five years and I will end up by ongoing research and future directions.

Practical information

  • General public
  • Free
  • This event is internal

Organizer

  • EESS - IIE

Contact

Tags

DOM refractory organic matter NMR bulk radiocarbon compound specific isotope analysis carbohydrates

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