Humin is a major fraction of soil organic matter and strongly affects the sorption behavior and fate of organic contaminants in soils and sediments. This study evaluated four different extraction methods for soil humins in terms of their organic @entity505 structural changes and the consequent effects on @entity11966 sorption. Solid-state @entity7352 NMR demonstrated that 0.1 M @entity6674 exhaustively extracted humin and humin extracted with 6 M HF/ @entity5828 at 60 degrees C had a relatively high amount of aliphatic components as compared with 1 M HF-extracted humin. The treatment of 6 M HF/ @entity5828 at 60 degrees C greatly reduced @entity1735 components (50-108 ppm) from humin samples, i.e., more than 50% reduction. In addition, the humin from this 6 M HF/ @entity5828 treatment contained relatively more amorphous @entity10256 domains than the humins extracted by other methods. With the respect to @entity11966 sorption, the linearity of sorption isotherm (N) and sorption affinity (Koc) varied markedly among the humin samples extracted by different methods. The @entity6674 exhaustively extracted humin had the most nonlinear sorption isotherm and the HF-extracted humin had the lowest Koc. It is concluded that humin samples from different extraction procedures exhibited substantial differences in their organic @entity505 structure and sorption characteristics, even though they were from the same soil. Therefore, one needs to be cautious when comparing the structural and sorption features of soil humins, especially when they are extracted differently. The 6 M @entity5828 /HF extraction at elevated temperature is not encouraged, due to the modifications of chemical structure and physical conformation of organic matter.

Chemical extractions affect the structure and XXXX sorption of soil humin.

@entity7352 :: ('CHEBI:36928', 'Chemical') :: ['13C'] @entity1735 :: ('CHEBI:16646', 'Chemical') :: ['carbohydrate'] @entity5828 :: ('CHEBI:17883', 'Chemical') :: ['HCl'] @entity6674 :: ('CHEBI:32145', 'Chemical') :: ['NaOH'] @entity10256 :: ('CHEBI:53551', 'Chemical') :: ['poly(methylene)'] @entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity11966 :: ('MESH:C031181', 'Chemical') :: ['phenanthrene']
@entity11966 :: (MESH:C031181,Chemical) :: ['phenanthrene']
