title: Quantitative EPR study on free radicals in the natural polyphenols interacting with metal ions and other environmental pollutants.
abstract: Quantitative electron paramagnetic resonance (EPR) method was applied to characterise radicals stabilised in polyphenolic matrices of various biogenic materials: lichens, mosses, composts, soils, peats, brown coals and sewage sludge sediments. The investigations were carried out on raw materials and extracted fractions of humic acids (HA). General trends of g value and spin concentration changes were found. These parameters in lichens strongly depend on lichen species and air pollution. Determination of the g value and semiquinone spin concentration allows to assess degree of transformation of organic matter in compost, soil, peat and lignite. Application of gaseous ammonia as a base penetrating the organic matrices extends the possibilities and usefulness of the method. Interaction of metal ions with humic materials is illustrated by interaction of VO2+ ion with peat and lignite HA as well as demineralised (raw and carbonised) brown coal. Our investigations demonstrate that quantitative EPR is a rapid and effective monitoring method to study the influence of various environmental factors on substances containing polyphenolic matrices.
authors: Faculty of Chemistry, Wroclaw University, Poland. adam@wchuwr.chem.uni.wroc.pl
authors: Adam
authors: A
authors: Jezierski
authors: Franciszek
authors: F
authors: Czechowski
authors: Maria
authors: M
authors: Jerzykiewicz
authors: Iwona
authors: I
authors: Golonka
authors: Jerzy
authors: J
authors: Drozd
authors: Ewa
authors: E
authors: Bylinska
authors: Yona
authors: Y
authors: Chen
authors: Mark R D
authors: MR
authors: Seaward
mesh_terms: D019068:Bryopsida; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D005419:Flavonoids; D005609:Free Radicals; D007477:Ions; D008011:Lichens / Q000737:chemistry; D008031:Lignin; D009584:Nitrogen / Q000032:analysis; D010636:Phenols / Q000737:chemistry*; D011044:Poland; D011108:Polymers / Q000737:chemistry*; D059808:Polyphenols; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis; D013696:Temperature; D013997:Time Factors
chemical_list: D004785:Environmental Pollutants; D005419:Flavonoids; D005609:Free Radicals; D007477:Ions; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D002244:Carbon; D008031:Lignin; D009584:Nitrogen