Reversed-phase high-performance liquid chromatography of the stable electrophoretic fractions of soil humic acids

Trubetskoi, O. A.; Trubetskaya, O. E.

doi:10.1134/s106422931502012x

Cited by 17 publications

(11 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first is a possible change in hydrogel structure. As described above, the structure of humic acids can be characterized by a supramolecular arrangement of relatively small particles, e.g., [6,8,11,12,13], often in co-existence with bigger macromolecules [9,13,14,15,16,17]. The structure of humic acids is very dynamic and sensitive to circumstances (concentration, pH, ionic strength) [21,22].…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

How Humic Acids Affect the Rheological and Transport Properties of Hydrogels

2019

View full text Add to dashboard Cite

Humic acids are often regarded as substances with a supramolecular structure which plays an important role in Nature. Their addition into hydrogels can affect their behavior and functioning in different applications. This work is focused on the properties of widely-used hydrogel based on agarose after addition of humic acids–the protonated H-form of humic acids and humic acids with methylated carboxylic groups. Hydrogels enriched by humic acids were studied in terms of their viscoelastic and transport properties. Rotational rheometry and methods employing diffusion cells were used in order to describe the influence of humic acids on the properties and behavior of hydrogels. From the point of view of rheology the addition of humic acids mainly affected the loss modulus corresponding to the relaxation of hydrogel connected with its flow. In the case of diffusion experiments, the transport of dyes (methylene blue and rhodamine) and metal ions (copper and nickel) through the hydrogel was affected by interactions between humic acids and the diffusion probes. The time lag in the hydrogel enriched by humic acids was prolonged for copper, methylene blue and rhodamine. In contrast, the presence of humic acids in hydrogel slightly increased the mobility of nickel. The strongest influence of the methylation of humic acids on diffusion was observed for methylene blue.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Nebbioso and Piccolo [12] developed a “humeomics” approach to characterize the structure of humic substances based on sequential chemical fractionation. Other authors [9,13,14,15,16,17] have confirmed that supramolecular associations and macromolecules can co-exist in the structure of humic acids.…”

Section: Introductionmentioning

confidence: 85%

How Humic Acids Affect the Rheological and Transport Properties of Hydrogels

2019

View full text Add to dashboard Cite

show abstract

“…Thus, in contrast to earlier views on HS structure which persisted for most of the 20th century, a current view regards HS as neither aromatic nor recalcitrant but rather as an assemblage of largely aliphatic and carbohydrate-derived structures that during the humification process acquire some lignin-like structures [128,165]. However, and as stated by Trubetskoi and Trubetskaya [166], while a supra-molecular concept for HS structure is plausible, unequivocal elucidation awaits confirmation. These authors go further and entertain the possibility, based on intensive physicochemical analyses, that HS aggregates may indeed comprise vesicles, as initially proposed by Wershaw [167], and that during alkaline isolation, these structures either form or are released from organo-mineral complexes following degradation of the membrane layer.…”

Section: On the Origin Supramolecular Aggregation And Mode Of Action Of Humic Substancesmentioning

confidence: 79%

Elaboration of a Phytoremediation Strategy for Successful and Sustainable Rehabilitation of Disturbed and Degraded Land

et al. 2022

View full text Add to dashboard Cite

Humans are dependent upon soil which supplies food, fuel, chemicals, medicine, sequesters pollutants, purifies and conveys water, and supports the built environment. In short, we need soil, but it has little or no need of us. Agriculture, mining, urbanization and other human activities result in temporary land-use and once complete, used and degraded land should be rehabilitated and restored to minimize loss of soil carbon. It is generally accepted that the most effective strategy is phyto-remediation. Typically, phytoremediation involves re-invigoration of soil fertility, physicochemical properties, and its microbiome to facilitate establishment of appropriate climax cover vegetation. A myco-phytoremediation technology called Fungcoal was developed in South Africa to achieve these outcomes for land disturbed by coal mining. Here we outline the contemporary and expanded rationale that underpins Fungcoal, which relies on in situ bio-conversion of carbonaceous waste coal or discard, in order to explore the probable origin of humic substances (HS) and soil organic matter (SOM). To achieve this, microbial processing of low-grade coal and discard, including bio-liquefaction and bio-conversion, is examined in some detail. The significance, origin, structure, and mode of action of coal-derived humics are recounted to emphasize the dynamic equilibrium, that is, humification and the derivation of soil organic matter (SOM). The contribution of plant exudate, extracellular vesicles (EV), extra polymeric substances (EPS), and other small molecules as components of the dynamic equilibrium that sustains SOM is highlighted. Arbuscular mycorrhizal fungi (AMF), saprophytic ectomycorrhizal fungi (EMF), and plant growth promoting rhizobacteria (PGPR) are considered essential microbial biocatalysts that provide mutualistic support to sustain plant growth following soil reclamation and restoration. Finally, we posit that de novo synthesis of SOM is by specialized microbial consortia (or ‘humifiers’) which use molecular components from the root metabolome; and, that combinations of functional biocatalyst act to re-establish and maintain the soil dynamic. It is concluded that a bio-scaffold is necessary for functional phytoremediation including maintenance of the SOM dynamic and overall biogeochemistry of organic carbon in the global ecosystem

show abstract

“…One of them can be their difference in molecular organization of humic and fulvic acids [12,25,26,36,40]. In general, supramolecular associations and macromolecules can co-exist in the structure of humic acids [41][42][43] and a supramolecular arrangement is usually proposed for fulvic acids [44]. Nuzzo and Piccolo [40] indicated the possibility of increasing the molecular size of supramolecular structures via oxidative polymerization and formation of new covalent bonds, chemically stabilizing humic substances.…”

Section: Discussionmentioning

confidence: 99%

New possibility for characterization of dissociation behaviour of supramolecular electrolytes: results obtained for the International Humic Substances Society standard and reference samples by coulometry

Klučáková

2021

Chem. Biol. Technol. Agric.

View full text Add to dashboard Cite

Background Humic substances can be considered as polyelectrolytes with supramolecular character and complicated behaviour in water environment. The fractions of humic substances dissolved in water are the most active ones and determinative for their functioning in nature, where the proton-binding and dissociation ability play a crucial role. The dissociation behaviour of humic and fulvic acids can be affected by different circumstances including their concentration which is directly connected with the molecular organization of humic particles in solution and the accessibility of their ionizable functional groups. This study is focused just on these active fractions and their dissociation behaviour in the dependence on their content in studied system. Results Standards and reference samples of International Humic Substances Society were used. Flow-through coulometry was used to determine the total content of acidic functional groups in fulvic solutions and humic leachates. The amount of dissociated acidic groups was determined on the basis of potentiometry. Several differences between the behaviour of humic and fulvic acids were found. While whole samples of fulvic acids including the weakest functional groups were analysed, only the active dissolved humic fractions containing stronger acidic functional groups were characterized. The fractions containing higher amounts of the weakest functional groups remained insoluble. The dissociation degree of fulvic acids decreased with their increasing content, but a maximum on its concentration dependence obtained for humic acids was observed. Conclusions Two different values of dissociation constants were determined for each sample. The first was determined on the basis of the extrapolation of infinite dilution, second was determined as their average value in the region of high concentrations in which it was constant. Obtained values characterize the functioning of dissolved humic substances from point of view of their dissociation ability. The results obtained by this approach can help to predict the acid–base behaviour of dissolved organic carbon in soil and generally in nature. The acid–base behaviour of dissolved organic carbon depends on its ratio to water. It behaves differently in soil which is dry and in soil which is wet or saturated by water.

show abstract

Reversed-phase high-performance liquid chromatography of the stable electrophoretic fractions of soil humic acids

Cited by 17 publications

References 44 publications

How Humic Acids Affect the Rheological and Transport Properties of Hydrogels

How Humic Acids Affect the Rheological and Transport Properties of Hydrogels

Elaboration of a Phytoremediation Strategy for Successful and Sustainable Rehabilitation of Disturbed and Degraded Land

New possibility for characterization of dissociation behaviour of supramolecular electrolytes: results obtained for the International Humic Substances Society standard and reference samples by coulometry

Contact Info

Product

Resources

About