English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Aquatic humic (HA) and fulvic acids (FA) from two different origins were fractionated by the tandem size-exclusion chromatography and polyacrylamide gel electrophoresis (tandem SECPAGE). Three HA and two FA fractions exhibited different molecular sizes, electrophoretic mobilities and structural compositions based on elemental analyses and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) after tetramethyl-ammonium hydroxide (TMAH) treatment. Based on comparison of the size-separates and unfractionated bulk samples, the highest molecular size fractions of aquatic humic substances (HS) appear to be enriched in fatty acids (mainly C16 and C18), which are strictly linked to the humic core. This and the presence of low chain fatty acids and unsaturated and di-tri acids may suggest a microbial rather than a vascular plant origin. Even if the majority of lignin derived components in aquatic HS represent relatively high state of biodegradation (oxidation), a certain variation between different sizefractions also exists, supporting a high heterogeneity and composite nature of aquatic HS. Although SEC-PAGE fractionation appears to produce fairly homogeneous HS fractions, the absorption of some urea into of the separates cannot be completely avoided in this method, which limits its suitability for evaluating, especially the presence of N-containing constituents.

arkivoc

Tandem size-exclusion chromatography-polyacrylamide gel electrophoresis fractionation of aquatic humic substances: characterization of size-separates with TMAH treatment and pyrolysis-GC/MS