Archives de l’auteur : webmaster

The OpenFluor database

For those who are interested in PARAFAC, below is the update I promised on the new tools discussed in my presentation.

(1)  The drEEM toolbox, providing extended tools for visualisation and validation of models is now available at http://www.models.life.ku.dk/drEEM

(2) The OpenFluor database, for quantitatively comparing NOM-PARAFAC components, will be available as soon as possible at www.OpenFluor.org. If you have published PARAFAC models that you would like to add to the database at the pre-release stage, please drop me a line. I will email instructions. Models submitted before Nov. 15 will be available for matching as soon as the website goes live. Once the website is live, you can go to www.OpenFluor.org and follow the instructions there to upload models directly.

Quantification of natural organic matter

Quantification of natural organic matter: caveats and needs

M. Filella1,2

1 Institute F.-A. Forel, Université de Genève, 10 route de Suisse, CH-1290 Versoix, Switzerland
2 SCHEMA, Rue Principale 92, L-6990 Rameldange, Luxembourg

Natural organic matter (NOM) plays an important role in many environmentally-relevant processes. NOM includes many different types of compounds, not all of which behave similarly. Much effort has gone into characterising some fractions of NOM (e.g., humic substances) in the different environmental compartments, in finding tracers to ascertain their origin, etc. –sometimes by using extremely sophisticated techniques–, but no comparable effort has been put into developing quantification techniques. As a result, field studies have often limited themselves to measuring only total (TOC) or dissolved (DOC) organic carbon or some surrogate parameter.

Quantification of NOM fractions in waters is not straightforward. Any analytical method measures a property of an analyte (or its reaction product) but the operationally defined nature of some NOM categories, together with the concomitant elusive and non-constant composition and structure of some of these substances, makes it difficult to find such an intrinsic property for them. Moreover, results have to be expressed as a function of the response of a standard, which is perceived as unsatisfactory by some users and, more importantly, remains largely misunderstood by many.

Four different cases will be discussed:

  • carbohydrates (or “when not all sugar is glucose”),

  • thiols,

  • TEP (a completely operational category),

  • ‘humics’ (the most difficult case?).

The importance of being able to quantify different types of NOM will be discussed in three different fields: thermodynamic modelling of trace element speciation (and implications for their use in ecotoxicology models such as BLM), understanding the fate of natural colloids and nanoparticles in freshwaters, studying long-term trends of NOM concentrations in relation to global climatic change.

Invited Conferences

 

Mostofa KHAN – David BRIE – Olivier ZiELINSKI – Debora MILORI

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M. Khan (Institute of Surface-Earth System Science)   : Professor at the Institute of Surface-Earth System Science, Tianjin University, China. He received his double MS (Chemistry, Jahangirnagar University, Bangladesh in 1992; and Earth and Planetary Science, Nagoya University, Japan in 2001) and PhD in 2005 from the Hiroshima University, Japan. Dr. Mostofa worked for eight years (2006-2014) at the IGCAS, first as a Postdoctoral Fellow (2006-2008), and then as an Associate Professor. His research focusses on photobiogeochemistry of organic matter.

« Characterisation and classification of fluorescent dissolved organic matter in water: Current challenges and future directions »

  • Shammi, M., Pan, X., Mostofa, K. M. G., Zhang, D., & Liu, C. Q. (2017). Photo-flocculation of microbial mat extracellular polymeric substances and their transformation into transparent exopolymer particles: Chemical and spectroscopic evidences. Scientific Reports, 7(1), 1–12. http://doi.org/10.1038/s41598-017-09066-8
  • Mostofa, K. M. G., Liu, C. Q., Vione, D., Gao, K., & Ogawa, H. (2013). Sources, factors, mechanisms and possible solutions to pollutants in marine ecosystems. Environmental Pollution, 182, 461–478. http://doi.org/10.1016/j.envpol.2013.08.005
  • Mostofa, K. M. G., & Sakugawa, H. (2009). Spatial and temporal variations and factors controlling the concentrations of hydrogen peroxide and organic peroxides in rivers. Environmental Chemistry, 6(6), 524–534. http://doi.org/10.1071/EN09070
  • Mostofa, K. M. G., Liu, C.-Q., Zhai, W., Minella, M., Vione, D., Gao, K., … Sakugawa, H. (2016). Reviews and Syntheses: Ocean acidification and its potential impacts on marine ecosystems. Biogeosciences, 13(6), 1767–1786. http://doi.org/10.5194/bg-13-1767-2016

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  D. BRIE (Centre de Recherche en Automatique de Nancy )  ,

 

 

 

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O. Zielinski (ICBM, Oldenburg) – Allemagne  : Prof. Dr. Oliver Zielinski is director of the Institute for Chemistry and Biology of the Marine Environment (ICBM) of the University of Oldenburg and head of the research group “Marine Sensor Systems”. His research activities focus on the development of innovative methods and sensors for marine observation, especially based on optical and acoustic principles. In 1999, he completed his doctorate in physics at the University of Oldenburg. After that, he moved to industry where he became scientific director and CEO of “Optimare Group”, an international supplier of marine sensor systems. In 2005, he was appointed professor at the University of Applied Science in Bremerhaven, Germany. In 2007, he became director of the Institute for Marine Resources (IMARE). After that, he returned to the University of Oldenburg in 2011. His area of research covers marine optics and marine physics, with a special focus on coastal systems, marine sensors and operational observatories while involving different user groups and stakeholders. (URLs : http://www.icbm.de, http://www.icbm.de/en/marine-sensor-systems/

  • Pearlman J, Zielinski O (2017) A new generation of optical systems for ocean monitoring – matrix fluorescence for multifunctional ocean sensing. Sea Technology, 2, pp 30-33
  • Miranda ML, Mustaffa NIH, Robinson TB, Stolle C, Ribas-Ribas M, Wurl O, Zielinski O (2018) Influence of solar radiation on biogeochemical parameters and fluorescent dissolved organic matter (FDOM) in the sea surface microlayer of the southern coastal North Sea. Elem Sci Anth, 6: 15. DOI: https://doi.org/10.1525/elementa.278

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D. MILORI (EMBRAPA Instrumentation) : Physicist, graduated from the University of Sao Paulo, Master and Ph.D. degrees in Physics from IFSC-USP. She has experience on Optical and Photonic methods of analysis, acting on the following subjects: soil organic matter, nutrients and contaminants and plant diseases. http://www.researcherid.com/rid/D-3875-2011.
« Soil organic matter in podzol horizons of the Amazon region:
Humification, recalcitrance, and dating »

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