Publications by authors named "M Harir"

Dissolved organic matter (DOM) is one of the most complex, dynamic and abundant sources of organic carbon, but its chemical reactivity remains uncertain. Greater insights into DOM structural features could facilitate understanding its synthesis, turnover and processing in the global carbon cycle. Here we use complementary multiplicity-edited C nuclear magnetic resonance (NMR) spectra to quantify key substructures assembling the carbon skeletons of DOM from four main Amazon rivers and two mid-size Swedish boreal lakes.

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Background: The rhizosheath, a cohesive soil layer firmly adhering to plant roots, plays a vital role in facilitating water and mineral uptake. In pearl millet, rhizosheath formation is genetically controlled and influenced by root exudates. Here, we investigated the impact of root exudates on the microbiota composition, interactions, and assembly processes, and rhizosheath structure in pearl millet using four distinct lines with contrasting soil aggregation abilities.

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Article Synopsis
  • The analysis of samples from the asteroid Ryugu reveals a rich diversity of soluble organic molecules, indicating complex chemistry on this C-type asteroid.
  • The study utilizes methods like mass spectrometry and nuclear magnetic resonance spectroscopy to explore the molecular characteristics of the samples, highlighting various polarities and sizes.
  • Findings suggest a water-rich environment for Ryugu's parent body, evidenced by compounds like ammonium ions and sulfidic substances, pointing to processes like carbonization and low-temperature aqueous alteration that contribute to the organic complexity.
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Selectivity in solid-phase extraction (SPE) materials has become increasingly important for analyte enrichment in sensitive analytical workflows to alleviate detrimental matrix effects. Molecular-level investigation of matrix constituents, which are preferentially extracted or excluded, can provide the analytical chemist with valuable information to learn about their control on sorbent selectivity. In this work, we employ nontargeted Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to elucidate the molecular chemodiversity of freshwater-derived dissolved organic matter (DOM) extracted by the selective model sorbent β-cyclodextrin polymer (β-CDP) in comparison to conventional, universal SPE sorbents (i.

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Cyclodextrin polymers (CDPs) are promising next-generation adsorbents in water purification technologies. The selectivity of the polymer derivate cross-linked with tetrafluoroterephthalonitrile (TFN-CDP) for nonionic and cationic micropollutants (MPs) over dissolved organic matter (DOM) renders the adsorbent also attractive for many analytical applications. The molecular drivers of the observed selectivity are, nonetheless, not yet fully understood.

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