Relationships between structure and binding affinity of humic substances for polycyclic aromatic hydrocarbons: relevance of molecular descriptorsстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:Partition coefficients for the binding affinities of pyrene, fluoranthene and anthracene to 26 different humic materials were determined by fluorescence quenching. Sources included isolated humic acids, fulvic acids, and combined humic and fulvic fractions from soil, peat, and fresh water as well as Aldrich humic acid. Each of the humic materials was characterized by elemental composition, ultraviolet absorbance at 280 nm, molecular weight, and for 19 samples, composition of main structural fragments determined by 13C solution-state NMR. The magnitude of the Koc values correlated strongly with the independent descriptors of aromaticity of humic materials, including atomic H/C ratio, absorptivity at 280 nm and three interdependent 13C NMR descriptors (CAr H,R, *CAr, *CAr/*CAlk). Statistical comparison of humic sources grouped by the origin revealed that binding affinities were best predicted by the 13C NMR descriptors, with a slight prevalence of *CAr/*CAlk ratio, while molecular weight was the poorest predictor. The latter produced either direct or inverse significant correlation with the Koc values depending upon the origin and/or fractional composition of the grouped humic materials.