Wydział Chemii

Adam Jezierski

Grzegorz Skrzypek

Piotr Jezierski

D. Paul

Mariusz Orion Jedrysek

2008

Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy

A69

1311-1316

10.1016/j.saa.2007.09.024

Naukowa

Angielski

Artykuł

EPR spectroscopy was performed on four peat cores (1–2.5 m depth) collected from Yellowstone National Park (USA), Scotland (UK) and Lower Silesia (Poland) to study peat formation process. The stable free radicals identified in all investigated samples are semiquinone type and g-parameters range from 2.0030 to 2.0048. The highest g-values are characteristic of upper well-aerated peat layers and gradually decrease with depth. The lowest g-values are typical of relatively old fens and bogs where anaerobic conditions are expected and carbonization processes are advanced. The decrease in g-parameter value is connected with conjugation of semiquinone units with gradually augmented polyaromatic units in the peat substance.Generally the radical concentration increases with depth (0.05–5 × 10¹⁷ spins/gram). However the g-values, line width parameters, and spin concentrations exhibit strong variations in some peat layers. Variation of these parameters observed for certain peat horizons correlate with the variation of carbon stable isotopic composition. For the old well-conserved peat deposits (e.g. Scotland/UK, ∼5600BP), variation of EPR parameters may be used to study paleo redox conditions.

Peat, Semiquinones, EPR, Paleoenvironmenta, Stable isotope

https://doi.org/10.1016/j.saa.2007.09.024

http://www.elsevier.com