title: Spectromicroscopy mapping of colloidal/particulate organic matter in Lake Brienz, Switzerland.
abstract: Transmission electron microscopy (TEM), soft X-ray scanning transmission X-ray microscopy (STXM), and mu-FTIR spectromicroscopy were used to map colloidal/ particulate material in an ultra-oligotrophic lake, Lake Brienz, Switzerland, with a special focus on organic functionality. Within the statistical margin of error and the uncertainties arising from the representativeness of the results, the research reveals that organic material was associated with potassium-rich inorganic colloids present in surface and deep water (depths of 1 and 100 m, respectively), which indicates a vertical transfer of aggregates by sedimentation. Pure organic colloids could only be detected in surface waters. In addition, correlation map analysis of synchrotron-based mu-FTIR and carbon K-edge STXM spectromicroscopic data using spectra from the Lütschine and Aare Rivers as target spectra revealed spectral similarities with organic components from both tributary rivers in deeper regions (100 m) of the lake. The results prove that STXM and mu-FTIR can characterize colloidal and particulate organic material in low organic carbon systems.
authors: Institut für Nukleare Entsorgung (INE), Forschungszentrum Karlsruhe, P.O. Box 3640, D-76021 Karlsruhe, Germany,
authors: Thorsten
authors: T
authors: Schäfer
authors: Vincent
authors: V
authors: Chanudet
authors: Francis
authors: F
authors: Claret
authors: Montserrat
authors: M
authors: Filella
mesh_terms: D002244:Carbon / Q000032:analysis; D002625:Chemistry, Organic; D016000:Cluster Analysis; D003102:Colloids / Q000737:chemistry; D004777:Environment; D008853:Microscopy / Q000379:methods*; D046529:Microscopy, Electron, Transmission; D009930:Organic Chemicals / Q000032:analysis*; D055601:Organic Chemistry Phenomena; D052638:Particulate Matter; D011188:Potassium / Q000737:chemistry; D025341:Principal Component Analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013557:Switzerland; D014867:Water; D014965:X-Rays
chemical_list: D003102:Colloids; D009930:Organic Chemicals; D052638:Particulate Matter; D014867:Water; D002244:Carbon; D011188:Potassium