Spectroscopic and structural characterization of a Laurentian fulvic acid: notes on the origin of the color

Zhendi, Wang; Pant, Bhuvan C.; Langford, Cooper H.

doi:10.1016/s0003-2670(00)81224-6

Cited by 93 publications

(54 citation statements)

References 7 publications

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“…Langford and is obtained from a sample of podzol (Laurentian Forest Preserve) near Quebec, Canada. The preparation and a first characterization of the sample have been reported by Wang et al [42];…”

Section: Methodsmentioning

confidence: 99%

Binding of cationic surfactants to humic substances

Ishiguro

Tan

Koopal

2007

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged.Binding of the cationic surfactants dodecyl-pyridinium chloride (DPC) and cetyl-or hexadecyl- binding to HS is due both to electrostatic and hydrophobic attraction and that the fate of HS in aqueous environmental systems can be strongly affected by cationic surfactants.

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Section: Methodsmentioning

confidence: 99%

Binding of cationic surfactants to humic substances

Ishiguro

Tan

Koopal

2007

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…The aromatic moieties in HSs are related to the levels of chromophore. 22 Thus, spectroscopic characteristics of the FAs were determined. First, the spectroscopic parameters of FAs (log E280 and log E465/E665) were compared.…”

Section: Chemical Characteristics Of Fasmentioning

confidence: 99%

Separation of Fulvic Acid from Soil Extracts Based on Ion-Pair Formation with a Cationic Surfactant

et al. 2006

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“…In many cases, the bulk properties are simply the summed or average contributions of individual molecules-for example, molecular weight, elemental composition and acidity. In other cases, properties like hemi-micelle formation in soil (Wershaw 1992) and non-linear optical phenomena (Wang et al 1990;Power et al 1986;Goldstone et al 2004) may arise from intermolecular interactions which in theory can be predicted from the properties of individual molecules.…”

Section: Introductionmentioning

confidence: 99%

A stochastic model for the synthesis and degradation of natural organic matter part II: molecular property distributions

et al. 2007

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A stochastic biogeochemical model has been developed to simulate the transformation and degradation of natural organic matter (NOM) using an agent-based algorithm which treats each molecule as a separate and potentially unique entity. Molecules react when a pseudo-random number is lower than the calculated reaction probability in a given time step; repeated time steps simulate the transformation of precursor molecules into a complex NOM assemblage. The data for each molecule-elemental and functional group composition-can be used to calculate many properties directly and exactly for each molecule in the assemblage, e.g., molecular weight (MW), fraction of aromatic C (Ar), and charge at pH 7 (Z). Empirical quantitative structure activity relationships (QSARs) are developed which permit the estimation of thermodynamic quantities K ow (the octanol-water partition coefficient) and pK a (acidity) for each molecule. Root mean square errors for these QSARs are 0.39 log units for log K ow and 0.45 log units for pK a . Distributions of both exactly calculated (MW, Ar, Z) and estimated thermodynamic (K ow , pK a ) properties are examined and compared with published experimental data. Molecular weight distributions from size exclusion HPLC experiments on aquatic NOM are quantitatively similar to simulation results. pH titrations and polarity distributions from reversed-phase HPLC are qualitatively similar to simulation results. This agreement suggests that the agent-based model can be used to explore hypotheses regarding both compositional and thermodynamic properties of NOM.Keywords Agent-based model Á Humic Á Natural organic matter Á Molecular weight Á Aromaticity Á Acidity Á Polarity Á QSAR Abbreviations a i constant value in a linear equation amu atomic mass units Ar aromaticity, the fraction of non-carbonyl sp 2 C in a molecule or group of molecules Robert Wetzel-deceased.

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Spectroscopic and structural characterization of a Laurentian fulvic acid: notes on the origin of the color

Cited by 93 publications

References 7 publications

Binding of cationic surfactants to humic substances

Binding of cationic surfactants to humic substances

Separation of Fulvic Acid from Soil Extracts Based on Ion-Pair Formation with a Cationic Surfactant

A stochastic model for the synthesis and degradation of natural organic matter part II: molecular property distributions

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