title: Aniline and 2,4,6-trinitrotoluene associate preferentially to low molecular weight fractions of dissolved soil organic matter.
abstract: Aniline and 2,4,6-trinitrotoluene (TNT) were equilibrated with particulate (POM) and dissolved organic matter (DOM) from an organic soil at different compositions of adsorbed major cations (Na, Al) and pH (aniline: 3.7-5.1, TNT: 4.8-5.0). After separation of POM, concentrations of (14)C-labelled aniline and TNT* (including TNT degradation products) were determined in DOM size fractions using size-exclusion chromatography (SEC) and UV-detection. Concentrations in the <3.5 kDa size fraction were 2.8-6.0 and 8.5-9.5 times higher for aniline and TNT*, respectively, as compared to the >40 kDa fraction. Thus, both aniline and TNT* were preferentially associated to the smallest DOM size fraction. The significant binding to DOM (similar extent as to POM) and the fact that the <3.5 kDa DOM fraction was less susceptible to flocculation by major metals suggests that the mobility of aniline and TNT is highly affected by the solubility of soil organic matter.
authors: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
authors: Johan
authors: J
authors: Eriksson
authors: Ulf
authors: U
authors: Skyllberg
mesh_terms: D000327:Adsorption; D000814:Aniline Compounds / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis*; D008970:Molecular Weight; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D014303:Trinitrotoluene / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D014303:Trinitrotoluene; C023650:aniline