A Nuclear Magnetic Resonance (NMR) and Fourier-Transform Infrared (FTIR) Study of Glycine Speciation on a Cd-Rich Montmorillonite

Leo, Paola Di

doi:10.1346/ccmn.2000.0480501

Cited by 21 publications

(3 citation statements)

References 27 publications

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“…Minerals such as montmorillonite, manganese oxides, and iron oxides are common in soils and are known to induce a variety of abiotic transformations of organic pollutants, including hydrolysis, oxidation–reduction, or rearrangement (e.g., refs − ). Grinding of minerals when they are loaded with organic pollutants was shown to enhance many abiotic transformations, for example, the mechanochemical degradation of atrazine and of 2,4-D on the surface of manganese oxide.…”

Section: Introductionmentioning

confidence: 99%

Mechanochemically Enhanced Degradation of Pyrene and Phenanthrene Loaded on Magnetite

Joseph-Ezra

Ahmed

Ben-Ari

et al. 2014

Environ. Sci. Technol.

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The enhancement of the degradation of polycyclic aromatic hydrocarbons (PAHs), exemplified by pyrene and phenanthrene, using mild grinding in the presence of common minerals was investigated. Magnetite, birnessite, and Na- and Cu-montmorillonite samples were loaded with pyrene or phenanthrene and ground manually or in a ball mill for short periods of time. The ground samples were analyzed for PAHs and for their metabolites, using high-performance liquid chromatography and liquid chromatography-mass spectrometry. No degradation of pyrene occurred when it was in contact with Na-montmorillonite or birnessite. Sorption of pyrene on Cu-montmorillonite enhanced its degradation, but grinding of the loaded clay actually inhibited pyrene's degradation. Phenanthrene hardly degraded on Cu-montmorillonite. Grinding magnetite loaded with either PAH resulted in a significant degradation of both (∼50% after grinding for 5 min), while in the nonground samples, negligible degradation was detected. The extent of degradation increased with the duration of grinding. The degradation of either PAH loaded on magnetite yielded oxidized products. In soil samples contaminated with PAHs and mixed with magnetite, a similar grinding-induced degradation pattern was observed, but with a lower rate. A liquid phase was required to initiate degradation in the soil. The liquid phase apparently served as the medium through which the pollutants reached the surface of the degradation-enhancing mineral.

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Section: Introductionmentioning

confidence: 99%

Mechanochemically Enhanced Degradation of Pyrene and Phenanthrene Loaded on Magnetite

Joseph-Ezra

Ahmed

Ben-Ari

et al. 2014

Environ. Sci. Technol.

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“…One group of bio-organic molecules, the amino acids and their derivates, play a major role in life as building blocks of biopolymers such as proteins and are used in many industrial applications, especially in adsorption, separation, and vectorization of organic molecules. , Over the years, many studies have investigated the intercalation of amino acids or other related molecules into clays for various purposes (see, e.g., refs − ).…”

Section: Introductionmentioning

confidence: 99%

Adsorption ofl-DOPA Intercalated in Hydrated Na-Saponite Clay: A Combined Experimental and Theoretical Study

Adraa¹,

Timón

Lambert³

et al. 2012

J. Phys. Chem. C

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The intercalation of L-DOPA into the interlayer space of saponite, a 2:1 phyllosilicate, and the nature of host−guest interactions are investigated by a combined experimental and theoretical approach. L-DOPA zwitterions are accommodated vertically in the interlayer region as a bilayer of partially interdigitated species. The hydration state of the nanocomposite as well as the interaction geometry of L-DOPA molecules in the clay interlayer, are determined by periodic DFT calculations and found to be in agreement with experimentally obtained data. New insights into the transport properties for biomolecules in saponite are discussed.

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“…Solid-state NMR has been successfully applied to amino acids in various environments: in bulk crystalline form, , or adsorbed on mineral surfaces such as TiO 2 , , hydrotalcites or clay minerals. , Chemical shifts can definitely discriminate between molecular arrangements that differ by the pattern of H-bonding or other weak interactions but the information they provide is sometimes hard to interpret. The power of NMR is also related to its ability to determine the atomic connectivities of molecules located on the surface since this spectroscopy is very sensitive to internuclear distances by taking advantage of through-space, dipolar interactions using for example cross-polarization (CP) experiments .…”

Section: Introductionmentioning

confidence: 99%

Leucine on Silica: A Combined Experimental and Modeling Study of a System Relevant for Origins of Life, and the Role of Water Coadsorption

et al. 2022

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Leucine on silica constitutes an interesting system from the point of view of origins of life studies since leucine coadsorbed on SiO 2 together with glutamic acid can give rise to rather long linear polypeptides upon activation. It is also an ideal system to test methods of molecular characterization of biomolecules deposited on mineral surfaces since it combines a small-scale model of peptides and proteins, which are among the most important components of biodevices, with one of the most widely used inorganic materials. We have deposited L-leucine on a high surface fumed silica in the submonolayer range and characterized it by a multipronged approach including macroscopic information (thermogravimetry, X-ray diffraction), in situ spectroscopic methods (IR, multinuclear solid-state NMR including single-pulse and CP-MAS, 2-D HETCOR), and molecular modeling by density functional theory (DFT), including calculation of NMR parameters. Specific information can be obtained on the adsorption and interaction mechanism. Leucine is rather strongly adsorbed without any covalent bonds, through the formation of a specific lattice of H-bonds that often involve coadsorbed water molecules. Its state is indeed strongly dependent on the drying procedure: insufficient drying results in liquid-like surroundings for the leucine functional groups, while vacuum drying only retains a limited number of waters (of the order of 5 per leucine molecule). The most stable models have zwitterionic leucine interacting directly with surface silanols through their ammonium group, while the carboxylate interacts through bridging waters. Experimental NMR chemical shifts are satisfactorily predicted for these models, and leucine can be viewed as a probe for specific groups of surface sites known as silanol nests.

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A Nuclear Magnetic Resonance (NMR) and Fourier-Transform Infrared (FTIR) Study of Glycine Speciation on a Cd-Rich Montmorillonite

Cited by 21 publications

References 27 publications

Mechanochemically Enhanced Degradation of Pyrene and Phenanthrene Loaded on Magnetite

Mechanochemically Enhanced Degradation of Pyrene and Phenanthrene Loaded on Magnetite

Adsorption ofl-DOPA Intercalated in Hydrated Na-Saponite Clay: A Combined Experimental and Theoretical Study

Leucine on Silica: A Combined Experimental and Modeling Study of a System Relevant for Origins of Life, and the Role of Water Coadsorption

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