scholarly journals Characterization of Double Leached Waelz Oxide for Identification of Fluoride Mineral

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 361 ◽  
Author(s):  
Suchandra Sar ◽  
Lena Sundqvist Ökvist ◽  
Tobias Sparrman ◽  
Fredrik Engström ◽  
Caisa Samuelsson
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Inductively Coupled Plasma ◽  
Raw Materials ◽  
Analytical Techniques ◽  
Optical Emission ◽  
Sem Analysis ◽  
Waelz Oxide ◽  
Production Knowledge ◽  
Nuclear Magnetic

Double leached Waelz oxide (DLWO), with 76% zinc, is a secondary zinc containing raw materials obtained by the treatment of electric arc furnace dust. The content of fluoride in DLWO is still too high for direct leaching, as fluoride has a detrimental effect on electrowinning for zinc production. Knowledge of the characteristics of DLWO, and especially on how a fluoride mineral might exist, can contribute to further improvement of the selective leaching for the removal of fluoride. In this study, DLWO was characterized using analytical techniques, such as inductively coupled plasma-optical emission spectroscopy (ICP-OES), 19F liquid-state nuclear magnetic resonance (19F LS NMR), X-ray powder diffraction analysis (XRD), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and 19F solid-state nuclear magnetic resonance (19F SS NMR). This study showed that DLWO mainly consisted of zincite (ZnO), cerussite (PbCO3) and a spinel containing zinc, iron and manganese. The fluoride mineral identified was calcium fluoride (CaF2). In SEM analysis, fluorine was found in larger grains together with calcium and oxygen, which was possibly calcium carbonate.

scholarly journals Nuclear Magnetic Resonance Spectroscopy for Medical and Dental Applications: A Comprehensive Review

2019 ◽  
Vol 13 (01) ◽  
pp. 124-128 ◽  
Author(s):  
Komal Zia ◽  
Talal Siddiqui ◽  
Saqib Ali ◽  
Imran Farooq ◽  
Muhammad Sohail Zafar ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Analytical Techniques ◽  
Resonance Spectroscopy ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Dental Applications ◽  
Insight Into ◽  
Nuclear Magnetic

AbstractNuclear magnetic resonance (NMR) spectroscopy is one of the most significant analytical techniques that has been developed in the past few decades. A broad range of biological and nonbiological applications ranging from an individual cell to organs and tissues has been investigated through NMR. Various aspects of this technique are still under research, and many functions of the NMR are still pending a better understanding and acknowledgment. Therefore, this review is aimed at providing a general overview of the main principles, types of this technique, and the advantages and disadvantages of NMR spectroscopy. In addition, an insight into the current uses of NMR in the field of medicine and dentistry and ongoing developments of NMR spectroscopy for future applications has been discussed.

An Application of the Polarizable Continnum Model for Obtaining Chalcones Magnetic Properties

2020 ◽  
Vol 12 (7) ◽  
pp. 939-950
Author(s):  
Agnes Jalowitzki Silva ◽  
Thaís F. Giacomello ◽  
Gunar V. da S. Mota ◽  
Antônio M. de J. Chaves ◽  
Fabio L. P. Costa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Population Distribution ◽  
Chemical Shifts ◽  
Biological Activities ◽  
Geometry Optimization ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Chalcones exhibit a wide variety of beneficial biological activities. In addition, these compounds include the prevention of diseases related to oxidative stress. The structural characterization of these molecules by means of analytical techniques can become a difficult task due to the complexity of some structures. However, cases of erroneously established natural product structure review are still found in the literature despite recent advances in spectroscopic techniques. Therefore, it is necessary to develop quantum calculation protocols that can aid in the correct structural ascertainment of these compounds. Thus, in this work, we tried to develop a parameterized protocol for calculations of chemical shift of carbon-13 nuclear magnetic resonance, in order to ensure a correct structural determination of polyphenols, with a focus on chalcones. For this, a series of molecules belonging to this class, with complex and varied structural skeletons, reliably elucidated in the literature, was selected and subjected to stochastic conformational searches using the Monte Carlo method and the Merk molecular force filed. The lower energy conformations of each molecule were selected for the geometry optimization step, performed at the mPW1PW91/6-31G(d) level. The chemical shifts of carbon-13 were calculated at the same level of theory, taking into account the population distribution of Boltzmann. The calculations were affected in both liquid phases, using the Polarizable Continuous Model as an implicit solvation model. The results show that the level of theory applied in the liquid phase allows a good reproduction of the experimental data. The application of the scaling factor allows the cancellation of systematic errors, which means that the values of scaled chemical shift are closer to the experimental ones. Thus, the parameterized protocol proved to be an important tool for the structural elucidation of polyphenols by calculations of carbon-13 nuclear magnetic resonance chemical shifts.

scholarly journals Surface NMR Using Quantum Sensors in Diamond

2021 ◽  
Author(s):  
Kristina Liu ◽  
Alex Henning ◽  
Markus W. Heindl ◽  
Robin Allert ◽  
Johannes D. Bartl ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Analytical Techniques ◽  
Kinetic Studies ◽  
Atomic Layer ◽  
Nitrogen Vacancy ◽  
Resonance Spectroscopy ◽  
Self Assembled Monolayer ◽  
Scientific Challenge ◽  
Nuclear Magnetic

Characterization of the molecular properties of surfaces under ambient or chemically reactive conditions isa fundamental scientific challenge. Moreover, many traditional analytical techniques used for probing surfaces often lack dynamic or molecular selectivity, which limits their applicability for mechanistic and kinetic studies under realistic chemical conditions. Nuclear magnetic resonance spectroscopy (NMR) is a widely used technique and would be ideal for probing interfaces due to the molecular information it provides noninvasively. However, it lacks the sensitivity to probe the small number of spins at surfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect nuclear magnetic resonance signals fromchemically modified aluminum oxide surfaces, prepared with atomic layer deposition (ALD). With the surfaceNV-NMR technique, we are able to monitor in real-time the formation kinetics of a self assembled monolayer (SAM) based on phosphonate anchoring chemistry to the surface. This demonstrates the capability of quan-tum sensors as a new surface-sensitive tool with sub-monolayer sensitivity for in-situ NMR analysis with theadditional advantage of a strongly reduced technical complexity.

scholarly journals Spectroscopic, Textural and Thermal Characterization Methods of Biostimulants Based on Sodium Humate

2019 ◽  
Vol 69 (12) ◽  
pp. 3477-3482
Author(s):  
Rusandica Stoica ◽  
Florin Oancea ◽  
Iulian Minca ◽  
Sanda Maria Doncea ◽  
Rodica Ganea ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Raw Materials ◽  
Nutrient Use Efficiency ◽  
Reference Method ◽  
Analytical Techniques ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Essential Information ◽  
Complex Investigation ◽  
Characterization Methods

Plant biostimulants, an emerging class of agricultural inputs, are complex products. The reproducibility of their specific action on plant metabolism and plant physiology, which lead to an enhanced nutrient use efficiency, stress tolerance and edible yield quality, is still a challenge. Development of quality insurance systems for plant biostimulants need complex investigation based on adapted analytical, physico-chemical and chemical methods. The objective of this work was to characterize commercial humate biostimulants through different analytical techniques (Fourier transform infrared spectroscopy - FTIR, thermogravimetric analysis- TGA) and to evaluate their textural and chemical (pH, C, N, humic acids, inorganic components) parameters. The first derivative curve from TG analysis showed decomposition of different compounds, classified according to the results obtained by FTIR. The humic substances determined by TGA method was comparable with the results obtained by gravimetric reference method. The inductively coupled plasma-optical emission spectrometry (ICP-OES) technique was applied to determine the inorganic elements either from the production process of humate or from raw materials, as well as for the control of humate in terms of requirements for safety and quality. Their complementary properties obtaining through different analytical techniques provide essential information on the chemical characteristics of the humate plant biostimulant formulations.

scholarly journals Validation of a Quantitative Proton Nuclear Magnetic Resonance Spectroscopic Screening Method for Coffee Quality and Authenticity (NMR Coffee Screener)

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Alex O. Okaru ◽  
Andreas Scharinger ◽  
Tabata Rajcic de Rezende ◽  
Jan Teipel ◽  
Thomas Kuballa ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Method ◽  
Screening Method ◽  
Analytical Techniques ◽  
Routine Screening ◽  
Proton Nuclear Magnetic Resonance ◽  
Detector Response ◽  
Roasted Coffee ◽  
Nuclear Magnetic

Monitoring coffee quality as a means of detecting and preventing economically motivated fraud is an important aspect of international commerce today. Therefore, there is a compelling need for rapid high throughput validated analytical techniques such as quantitative proton nuclear magnetic resonance (NMR) spectroscopy for screening and authenticity testing. For this reason, we sought to validate an 1H NMR spectroscopic method for the routine screening of coffee for quality and authenticity. A factorial experimental design was used to investigate the influence of the NMR device, extraction time, and nature of coffee on the content of caffeine, 16-O-methylcafestol (OMC), kahweol, furfuryl alcohol, and 5-hydroxymethylfurfural (HMF) in coffee. The method was successfully validated for specificity, selectivity, sensitivity, and linearity of detector response. The proposed method produced satisfactory precision for all analytes in roasted coffee, except for kahweol in canephora (robusta) coffee. The proposed validated method may be used for routine screening of roasted coffee for quality and authenticity control (i.e., arabica/robusta discrimination), as its applicability was demonstrated during the recent OPSON VIII Europol-Interpol operation on coffee fraud control.

scholarly journals Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (<sup>1</sup>H-NMR) analysis and HPLC HULIS determination

2017 ◽  
Vol 17 (17) ◽  
pp. 10405-10421 ◽  
Author(s):  
Nicola Zanca ◽  
Andrew T. Lambe ◽  
Paola Massoli ◽  
Marco Paglione ◽  
David R. Croasdale ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
1H Nmr ◽  
Flow Reactor ◽  
Analytical Techniques ◽  
Water Soluble ◽  
Proton Nuclear Magnetic Resonance ◽  
Aerosol Mass ◽  
Polycarboxylic Acids ◽  
Nuclear Magnetic

Abstract. The study of secondary organic aerosol (SOA) in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a potential aerosol mass (PAM) oxidation flow reactor using α-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically relevant photochemical ageing timescales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization – proton nuclear magnetic resonance (1H-NMR) spectroscopy and HPLC determination of humic-like substances (HULIS). Results were compared with previous Aerodyne aerosol mass spectrometer (AMS) measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquires spectroscopic features comparable to those of ambient OA when exposed to at least 1  ×  1012 molec OH cm−3  ×  s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent OH exposure, the formation of HULIS is observed in both α-pinene SOA and in naphthalene SOA (maximum yields: 16 and 30 %, respectively, of total analyzed water-soluble organic carbon, WSOC), providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

scholarly journals Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (<sup>1</sup>H-NMR) analysis and HPLC HULIS determination

2017 ◽  
Author(s):  
Nicola Zanca ◽  
Andrew T. Lambe ◽  
Paola Massoli ◽  
Marco Paglione ◽  
David R. Croasdale ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
1H Nmr ◽  
Flow Reactor ◽  
Maximum Yield ◽  
Analytical Techniques ◽  
Proton Nuclear Magnetic Resonance ◽  
Aerosol Mass ◽  
Polycarboxylic Acids ◽  
Nuclear Magnetic

Abstract. The study of secondary organic aerosol (SOA) in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a Potential Aerosol Mass (PAM) oxidation flow reactor using alpha-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically-relevant photochemical aging time scales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization – proton nuclear magnetic resonance (1H-NMR) spectroscopy and HPLC determination of humic-like substances (HULIS). Results were compared with previous Aerodyne aerosol mass spectrometer (AMS) measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquire spectroscopic features comparable to those of ambient OA when exposed to at least 1*1012 molec OH /cm3*s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent atmospheric OH exposure, the formation of HULIS is observed in both α-pinene SOA (maximum yield = 16 %) and in naphthalene SOA (maximum yield = 30 %), providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

scholarly journals Quantitative Determination of Dimethylaminoethanol in Cosmetic Formulations by Nuclear Magnetic Resonance Spectroscopy

2008 ◽  
Vol 91 (6) ◽  
pp. 1303-1308 ◽  
Author(s):  
Ivani Aparecida Soares De Andradebatista ◽  
Maria Inês De Almeida Gonçalves ◽  
Anil Kumar Singh ◽  
Erika Rosamaria Kedor Hackmann ◽  
Andmaria Inês Rochamiritello Santoro
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantitative Determination ◽  
Raw Materials ◽  
Spectroscopic Method ◽  
Resonance Spectroscopy ◽  
Relative Standard ◽  
Cosmetic Formulations ◽  
Nuclear Magnetic

Abstract A nuclear magnetic resonance (NMR) spectroscopic method was validated for the quantitative determination of dimethylaminoethanol (DMAE) in cosmetic formulations. The linearity in the range from 0.5000 to 1.5000 g (DMAE salt/mass maleic acid) presents a correlation coefficient &gt;0.99 for all DMAE salts. The repeatability (intraday), expressed as relative standard deviation, ranged from 1.08 to 1.44 for samples and 1.31 to 1.88 for raw materials. The detection limit and quantitation limit were 0.0017 and 0.0051 g for DMAE, 0.0018 and 0.0054 g for DMAE bitartrate, and 0.0023 and 0.0071 g for DMAE acetamidobenzoate, respectively. The proposed method is simple, precise, and accurate and can be used in the quality control of raw materials and cosmetic gels containing these compounds as active substances.

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