Relationships between structure and binding affinity of humic substances for polycyclic aromatic hydrocarbons: Relevance of molecular descriptors

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es990056x· OSTI ID:20000703

Perminova, I V; Grechishcheva, N Y; Petrosyan, V S

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 freshwater 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 {sup 13}C solution-state NMR. The magnitude of the K{sub oc} values correlated strongly with the independent descriptors of aromaticity of humic materials, including atomic H/C ratio, absorptivity at 280 nm, and three interdependent {sup 13}C NMR descriptors (C{sub Ar{minus}H,R}, {summation}C{sub Ar}, {summation}C{sub Ar}/{summation}C{sub Alk}). Statistical comparison of humic sources grouped by the origin revealed that binding affinities were best predicted by the {sup 13}C NMR descriptors. with a slight prevalence of {summation}C{sub Ar}/{summation}C{sub Alk} ration, while molecular weight was the poorest predictor. The latter produced either direct or inverse significant correlation with the K{sub oc} values depending upon the origin and/or fractional composition of the grouped humic materials.

• Research Organization: Lomonosov Moscow State Univ. (RU)
• OSTI ID: 20000703
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 21 Vol. 33; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AFFINITY
ENVIRONMENTAL TRANSPORT
FULVIC ACIDS
HUMIC ACIDS
MOLECULAR STRUCTURE
POLLUTION
POLYCYCLIC AROMATIC HYDROCARBONS
SOIL CHEMISTRY
WATER CHEMISTRY