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(searched for: Elemental Analysis Using Atomic Absorption Spectroscopy)
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Samira Zamani, Alireza Abbasi, Majid Masteri-Farahani, Saeed Rayati
New Journal of Chemistry; https://doi.org/10.1039/d1nj04828g

Abstract:
One-pot facile synthesis of a new composite based on the incorporation of a metalloporphyrin within the UiO-66 metal-organic framework is reported. To enhance the catalytic activity of UiO-66, pore modification with (CoTHPP(OAC)=meso-tetrakis(4-hydroxyphenylporphyrinato) cobalt(II)) was performed. For easy magnetic separation, Fe3O4 was introduced to the prepared composite. Characterization of the [email protected]@UiO-66 composite was performed by Fourier transform-infrared (FT-IR), ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, CHN elemental analysis, nitrogen adsorption-desorption isotherm (BET method), and X-ray diffraction (XRD) techniques. Oxidation of the olefins and allylic alcohols was done with tert-Butyl hydroperoxide (TBHP) in acetonitrile with excellent efficiency (95 % conversion) and 67% selectivity in the presence of [email protected]@UiO-66.
S. M. Mokhtar, , C. F. Soon, N. K. A. Hamed, M. Shimomura
Journal of Materials Science: Materials in Electronics pp 1-12; https://doi.org/10.1007/s10854-021-07440-x

The publisher has not yet granted permission to display this abstract.
Ahmed Magtouf AlWadi
Egyptian Journal of Chemistry; https://doi.org/10.21608/ejchem.2021.102312.4746

Abstract:
In this paper, we used the aqueous extract of the Zygophyllum Coccineum Plant Leaves for the synthesis of ZnO-NPs by a green method utilizing zinc acetate dihydrate as a precursor. The synthesized zinc oxide NPs was characterized by AFM (Atomic Force Microscopy), UV-Vis. (UV-Visible spectroscopy), FT-IR (Fourier Transform Infrared Spectroscopy). XRD (X-Ray Diffraction), FE-SEM (Field emission Scanning Electron Microscopy), and EDX (Energy Dispersive X-Ray Spectroscopy). We investigate the topography of the ZnO-NPs surface and it gave an average diameter of 67.42 nm. The wavelength of the sample was 368 nm and Eg was 3.3714 e. V. The absorption peak appears at 561 cm-1 which confirms the presence of ZnO-NPs nanoparticles. X-ray diffraction studies represent the size of crystallites 12.01 nm using the Debby-Scherrer formula that proposed ZnO-NPs have a hexagonal structure. The purity of zinc oxide NPs formation and the percentage of elements in nanoparticles structure were proven by EDX. SEM testing using the images of the ZnO-NPs proved that spherical shapes of nanoparticles agree with XRD analysis.
Ali Ammarellou, Valiollah Mozaffarian
Published: 12 November 2021
Scientific Reports, Volume 11, pp 1-8; https://doi.org/10.1038/s41598-021-01113-9

Abstract:
Folk medicine such as herbal and natural products have been used for centuries in every culture throughout the world. The Chenopodiaceae family with more than 1500 species is dispersed worldwide. The Iranian wild spinach (Blitum virgatum L.) is an important traditional medicinal plant used for antiviral diseases such as pneumonia and other respiratory track infections. This plant is a mountainous herb and is growing upper than 3000 m. We performed a mass selection plant breeding program on wild populations of this Iranian wild spinach during 2013–2020. Based on experimental and field characteristics this plant was identified as B. virgatum, |abbaricum|, and related characteristics were prepared with reference to the International Union for the Protection of New Varieties of Plants (UPOV). Mass selection program resulted from an adapted population named as medicinal spinach (MSP) population. To compare the mineral content of the mass-selected population with cultivated spinach (Spinacia oleracea L. |Varamin 88|), both plants were planted in pots and fields under similar conditions. In five leaves stage, plant samples were taken from both leaf and crown sections and used for experimental analysis. Atomic absorption spectroscopy was used to determine the mineral content including iron (Fe), zinc (Z), manganese (Mn), and copper (Cu). Our results showed the selected medicinal spinach population (MSP) with about 509 ppm iron was an important iron-rich population with about 3.5–4 times more than the amount of iron in cultivated spinach in the same conditions. Because iron is an important essential element for blood production, respiration process, energy metabolisms, synthesis of collagen, and some neurotransmitters are needed for proper immune function, so the supply of absorbable adequate iron is very important. The reasons such as the prevalence of the COVID-19 pandemic, which affects the amount of exchangeable oxygen in the lungs and historical local evidences of the use of this plant (MSP) for pneumonia, could open new horizons for focusing on studies related to the use of ancestral human experiences in addition to scientifically modern research.
, , C. Rojas-Ayala, P. Paucar Cabrera, C. V. Landauro, J. Quispe-Marcatoma, J. Rojas Tapia, E. M. Baggio-Saitovitch, E. C. Passamani
Published: 10 November 2021
Hyperfine Interactions, Volume 242, pp 1-16; https://doi.org/10.1007/s10751-021-01758-y

The publisher has not yet granted permission to display this abstract.
Abdul Moiz Mohammed
European Journal of Engineering and Technology Research, Volume 6, pp 48-51; https://doi.org/10.24018/ej-eng.2021.6.7.2639

Abstract:
The resonance radiation study is a powerful means in obtaining valuable information concerning the behavior of individual atoms and molecules. Various quantitative techniques are available in order to determine the amount of analyte and analysis of trace elements in the sample. Some technique uses the principle, when the number of atoms in the path of light increases, the amount of light absorption increases. While other techniques use dissociation of chemical compound free atoms by supplying enough thermal energy. In this paper, an attempt is made to compare various analytical methods with their merits and demerits and the reasons for popularity of atomic absorption spectroscopy among researchers. Elemental analysis using atomic absorption spectroscopy of various elements that are found in nature particularly in foods and environment is also presented.
Dollyca Ningombam, Hidangmayum Deliza, Bachaspatimayum Debkumari,
Journal of Pharmaceutical Research International pp 52-67; https://doi.org/10.9734/jpri/2021/v33i47b33096

Abstract:
Aim: The present study aims to investigate the phytochemical, antimicrobial and acute toxicity assay of methanol extract of Citrus medica L. fruit (CMF) and Citrus hystrix D.C. fruit (CHF). Place and Duration of Study: Fruit samples were collected between February to August 2018, at the Department of Life Sciences, Manipur University. Methodology: Phytochemical studies were conducted using Gas Chromatography-Mass Spectrometry (GC-MS), HR-LC-MS (High Resolution-Liquid Chromatography-Mass Spectrometry), Graphite Furnace-Atomic Absorption Spectrometry (GF-AAS), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) respectively. The standard filtered disc-diffusion method was used for antimicrobial assay. Acute toxicity was performed using 423-OECD guidelines. Results: GC-MS and HR-LC-MS analysis showed presence of Ranitidine, 4-Methylesculetin, Diosmin and Avobenzone in CMF whereas 9-Octadecenamide, Gamma-Sitosterol, n-Hexadecanoic acid, 2-Methoxy-4-Vinylphenol, Rhoifolin, Diosmin and Phytosphingosine in CHF. GF-AAS and ICP-OES study prominently showed Pb content in both the samples. Highest element in CMF was Pb (4.26±0.120 ppm) while in CHF was Cr (4.35±0.70 ppm). Antimicrobial study exhibited highest inhibitory effect of CMF against Staphylococcus aureus and Klebsiella pneumonia while CHF against Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus than Gentamicin (p<0.05). No toxicity behaviour and mortality in mice were observed during acute toxicity study period even at a dose of 5000 mg/kg body weight. Changes in serum constituent level were observed however, no genotoxicity was recorded. Conclusion: We concluded that CMF and CHF cultivation site selection should be the first step to avoid Pb content. The CMF and CHF have many health beneficial constituents. From this study also concluded that CMF and CHF may be a potential source of antiulcer, antimicrobial, antiarthritic, diuretic, antiinflammatory and anticancer effects. However, further study to understand whether changes in serum constituent level for prolonged period usages as medicine or nutraceuticals is highly recommended.
Published: 26 October 2021
by MDPI
Abstract:
A heterogeneous Janus-type palladium interphase catalyst was obtained by selective surface modification of a hollow mesoporous silica material. The catalyst comprises hydrophobic octyl groups on one side of the silica nanosheets and single-site bis-imidazoline dichlorido palladium(II) complexes on the other. The structure of this composite material has been analyzed by means of elemental analysis, atomic absorption spectroscopy, BET surface analysis, TGA, SEM and solid-state CP-MAS 13C and 29Si NMR spectroscopy. The catalyst showed extraordinary activity for the aqueous-phase oxidation of styrene to acetophenone using 30% hydrogen peroxide as the oxidant. An 88% yield of acetophenone could be achieved after 60 min.
Enerelt Urnukhsaikhan, Bum-Erdene Bold, AminaA Gunbileg, Nominchimeg Sukhbaatar, Tsogbadrakh Mishig-Ochir
Published: 26 October 2021
Scientific Reports, Volume 11, pp 1-12; https://doi.org/10.1038/s41598-021-00520-2

Abstract:
In recent years’ synthesis of metal nanoparticle using plants has been extensively studied and recognized as a non-toxic and efficient method applicable in biomedical field. The aim of this study is to investigate the role of different parts of medical plant Carduus crispus on synthesizing silver nanoparticles and characterize the produced nanoparticle. Our study showed that silver nanoparticles (AgNP) synthesized via whole plant extract exhibited a blue shift in absorption spectra with increased optical density, which correlates to a high yield and small size. Also, the results of zeta potential, X-ray diffraction, photon cross-correlation spectroscopy analysis showed the surface charge of − 54.29 ± 4.96 mV (AgNP-S), − 42.64 ± 3.762 mV (AgNP-F), − 46.02 ± 4.17 mV (AgNP-W), the crystallite size of 36 nm (AgNP-S), 13 nm (AgNP-F), 14 nm (AgNP-W) with face-centered cubic structure and average grain sizes of 145.1 nm, 22.5 nm and 99.6 nm. Another important characteristic, such as elemental composition and constituent capping agent has been determined by energy-dispersive X-ray spectroscopy and Fourier transform infrared. The silver nanoparticles were composed of ~ 80% Ag, ~ 15% K, and ~ 7.5% Ca (or ~ 2.8% P) elements. Moreover, the results of the FTIR measurement suggested that the distinct functional groups present in both AgNP-S and AgNP-F were found in AgNP-W. The atomic force microscopy analysis revealed that AgNP-S, AgNP-F and AgNP-W had sizes of 131 nm, 33 nm and 70 nm respectively. In addition, the biosynthesized silver nanoparticles were evaluated for their cytotoxicity and antibacterial activity. At 17 µg/ml concentration, AgNP-S, AgNP-F and AgNP-W showed very low toxicity on HepG2 cell line but also high antibacterial activity. The silver nanoparticles showed antibacterial activity on both gram-negative bacterium Escherichia coli (5.5 ± 0.2 mm to 6.5 ± 0.3 mm) and gram-positive bacterium Micrococcus luteus (7 ± 0.4 mm to 7.7 ± 0.5 mm). Our study is meaningful as a first observation indicating the possibility of using special plant organs to control the characteristics of nanoparticles.
Journal of King Saud University - Science, Volume 33; https://doi.org/10.1016/j.jksus.2021.101661

Abstract:
The present study accounts for cholest-5-en-7-one (steroid) synthesis using selenium dioxide and silica as well as its identification using high-resolution mass spectrometry (HRMS), FT-IR, NMR, and elemental analysis. Density functional theory (DFT) calculations were used to optimize the steroid's geometry, which was then compared to single-crystal X-ray diffraction data, indicating that the computational and experimental results were in good agreement. UV-vis absorption titration, fluorescence spectral methods, circular dichroism (CD), and dynamic light scattering (DLS)were used to investigate the well-identified steroid's in vitro molecular interaction with human serum albumin (HSA).The results and binding parameter indicate that the steroid has significant binding affinity for HSA. Molecular docking was performed and found that the steroid can interact with the hydrophobic cavity of HSA through hydrogen and hydrophobic contacts. Molecular dynamics simulation was used to confirm the stability of the HSA-steroid complex. Combined quantum mechanics-molecular mechanics (QM-MM) methods were applied to know binding energy of system and individual components for atomic level interactions indicating a significant interaction between the steroid and the biomacromolecules. The findings presented here contribute to a better understanding of steroid pharmacodynamics.
Brazilian Journal of Analytical Chemistry, Volume 8, pp 1-2; https://doi.org/10.30744/brjac.2179-3425.editorial.vgmihucz.n33

Abstract:
Since the early days of modern chemistry, analytical chemistry always tried to offer solutions to real-life problems. This is how, in the midst of the Industrial Revolution, Margueritte developed the titrimetric determination of iron using the chameleon solution (potassium permanganate). In 1860, for the first time, Bunsen and Kirchhoff used element-specific light emission and absorption of flame-evaporated alkali metal salts for qualitative analysis. Their discovery was groundbreaking because the analytical sensitivity and detection capability of the proposed method was several orders of magnitude lower than that of the contemporary classical analytical ones. Application of this method, leading to the establishment of spectroscopic techniques, also allowed the discovery of about ten chemical elements. Another timeless merit of spectroscopy is the ability to determine the elemental composition of a star in a distant galaxy. In the second half of the 20th century, an era of rapid development of instrumental analysis, atomic spectroscopy also brought several revolutionary results. One such breakthrough was the reduction of the sample volume required for analysis down to microliters with the introduction of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit of GFAAS also decreased by several orders of magnitude. Another important advance was the combination of inductively coupled plasma as a high-temperature ion source with a mass spectrometer (ICP-MS). In the late 1980s, the hyphenation of atomic spectrometric devices to chromatographs, aiming at elemental speciation, also emerged. In Central and Eastern Europe, spectroscopic research was driven by the embargo of the Coordinating Committee for Multilateral Export Controls established by the Western Bloc during the Cold War. In this emerging era, scientific research and applications went hand in hand. Therefore, the science education program and fundamental research were very strong in those countries, contributing considerably to the development of spectrochemistry in Hungary. By the end of the 20th century, development of new equipment and procedures was increasingly carried out by instrument manufacturers, and fundamental research at universities and institutes was relegated to second place. Analytical chemistry has experienced a considerable shift from determination of inorganic compounds and small organic molecules towards that of large (bio)molecules. Expansion of the application of analytical chemistry to forensic, environmental and biochemical questions has been observed and the role of atomic spectrometric techniques seemed to fade away. However, sheer use of these high-performance instruments is not always appropriate or cost-effective; the reliability of the results and elimination of interference must be thoroughly explored. However, when publishing such results, there is a risk that our communications will be rejected due to lack of novelty. Nevertheless, carrying out fundamental research cannot be avoided, as it is not possible to offer appropriate decisions to stakeholders based on questionable results. Presently, GFAAS and ICP-MS allow reliable quantitative determination of virtually any element in any sample. Recently, microwave plasma using nitrogen isolated from the air was launched on the market. This device requires significantly lower operating costs compared to the conventional ICP and reliable simultaneous multi-element analysis has also become possible. Another promising direction is single-particle ICP-MS applied for the characterization of inorganic nanoparticles. Most of the articles of the current issue of BrJAC also demonstrate that atomic spectrometry has become indispensable in many areas of our life. Enjoy reading the current issue!
I. Rehan, , R. K. Aldakheel, , K. Rehan, S. Khan, S. Sultana, M. Z. Khan
Arabian Journal for Science and Engineering pp 1-9; https://doi.org/10.1007/s13369-021-06233-y

The publisher has not yet granted permission to display this abstract.
Published: 25 September 2021
by MDPI
Abstract:
Humic substances (HS) are natural supramolecular systems of high- and low-molecular-weight compounds with distinct immunomodulatory and protective properties. The key beneficial biological activity of HS is their antioxidant activity. However, systematic studies of the antioxidant activity of HS against biologically relevant peroxyl radicals are still scarce. The main objective of this work was to estimate the antioxidant capacity (AOC) of a broad set of HS widely differing in structure using an oxygen radical absorption capacity (ORAC) assay. For this purpose, 25 samples of soil, peat, coal, and aquatic HS and humic-like substances were characterized using elemental analysis and quantitative 13C solution-state NMR. The Folin–Ciocalteu method was used to quantify total phenol (TP) content in HS. The determined AOC values varied in the range of 0.31–2.56 μmol Trolox eqv. mg−1, which is close to the values for ascorbic acid and vitamin E. Forward stepwise regression was used to reveal the four main factors contributing to the AOC value of HS: atomic C/N ratio, content of O-substituted methine and methoxyl groups, and TP. The results obtained clearly demonstrate the dependence of the AOC of HS on both phenolic and non-phenolic moieties in their structure, including carbohydrate fragments.
, Zbigniew Samczyński, Rajmund S. Dybczyński, Ewelina Chajduk, Bożena Danko, Paweł Kalbarczyk, Agnieszka A. Krata, Marta Pyszynska, Iga Zuba
Published: 21 September 2021
Food Analytical Methods pp 1-14; https://doi.org/10.1007/s12161-021-02081-6

Abstract:
Three new reference materials: MODAS-3 Herring Tissue (M-3 HerTis), MODAS-4 Cormorant Tissue (M-4 CormTis), and MODAS-5 Cod Tissue (M-5 CodTis) were prepared and certified on the basis of results of a worldwide intercomparison exercise. Independently of our proven method of establishing the certified and information values, the content of several essential and toxic elements was additionally determined by the use of ratio primary reference measurement procedures (definitive methods) based on radiochemical neutron activation analysis (RNAA) in the case of As, Cd, Co, Cr, Fe, Mo, Se, and U and isotope dilution mass spectrometry (IDMS) in the case of Hg, respectively. Good agreement of the established certified values and the results obtained by ratio primary reference measurement procedures confirmed the validity of the certification procedure. The total number of elements which could be certified amounted to 30, 21, 18 in M-3 HerTis, M-4 CormTis, and M-5 CodTis, respectively. The relative frequency of use of individual analytical techniques in this intercomparison campaign was calculated and discussed. Inductively coupled plasma mass spectrometry (ICP-MS) is now a dominant technique, followed by atomic absorption spectroscopy (AAS), NAA, and emission spectroscopy (ES). The decreasing share of NAA as compared to several earlier intercomparison exercises should be noticed. NAA is the only method in the array of highly sensitive methods of inorganic trace analysis, which is essentially free from blank. The lack of this method in the foreseeable future may be an obstacle in the prospective certification campaigns and may endanger the implementation of quality assurance in trace analysis.
Reyhaneh Toufanian, Xingjian Zhong, Joshua C. Kays, Alexander M. Saeboe,
Chemistry of Materials, Volume 33, pp 7527-7536; https://doi.org/10.1021/acs.chemmater.1c02501

Abstract:
The focus on heavy metal-free semiconductor nanocrystals has increased interest in ZnSe semiconductor quantum dots (QDs) over the past decade. Reliable and consistent incorporation of ZnSe cores into core/shell heterostructures or devices requires empirical fit equations correlating the lowest-energy electron transition (1S peak) to their size and molar extinction coefficients (ε). While these equations are known and heavily used for CdSe, CdTe, CdS, PbS, etc., they are not well established for ZnSe and are nonexistent for ZnSe QDs with diameters <3.5 nm. In this study, a series of ZnSe QDs with diameters ranging from 2 to 6 nm were characterized by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), UV–vis spectroscopy, and microwave plasma atomic emission spectroscopy (MP-AES). SAXS-based size analysis enabled the practical inclusion of small particles in the evaluation, and elemental analysis with MP-AES elucidates a nonstoichiometric Zn:Se ratio consistent with zinc-terminated spherical ZnSe QDs. Using these combined results, empirical fit equations correlating QD size with its lowest-energy electron transition (i.e., 1S peak position), Zn:Se ratio, and molar extinction coefficients for 1S peak, 1S integral, and high-energy wavelengths are reported. Finally, the equations are used to track the evolution of a ZnSe core reaction. These results will enable the consistent and reliable use of ZnSe core particles in complex heterostructures and devices.
Li Yiran
Published: 10 September 2021
Abstract:
The exploration and application of nanomaterials have been attracting researchers’ attention in recent decades. Nanocatalysts, as one of the very important classes of nanomaterials, have been developed for several generations. Nanotechnology makes light be possibly utilized in catalysis rather than only heat and allows multifunctional parts to be assembled in one catalyst. The TiO2 (as the representative of hetero-photocatalyst) and iron-based magnetic catalysts (as multifunctional catalyst) will be discussed in detail in this thesis. The first chapter will introduce the background of catalysts and nanomaterials. TiO2, especially black TiO2, will be mainly discussed in the aspects of properties, synthesis, and applications. Another part of the chapter will talk about the separation-friendly catalyst – magnetic heterogenous catalysts’ synthesis and applications. Chapter 2 focuses on the synthetic route we used and the characterization of black TiO2 catalysts and magnetic catalysts. Both anatase and rutile black TiO2 catalysts were successfully prepared originally from Degussa P25 using the ethanol reduction method. The re-whitening treatment was also examined on both black TiO2 catalysts. All catalysts were characterized and compared by diffuse reflectance (DR), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscope (XPS). Tauc plot results show that black TiO2 has smaller band gap than white TiO2. XPS revealed the existence of surface -OH species and Ti3+ in black TiO2. Furthermore, these two characterization techniques and XRD all proved that the blackening and re-whitening treatment does not change the crystalline phase of the catalysts, and the blackening treatment is reversible. For magnetic catalysts, we synthesized magnetic Fe2O3, [email protected], copper/iron oxide magnetic TiO2, and black magnetic catalysts. Other than diffuse reflectance spectroscopy, Raman spectroscopy, scanning electron microscopy, and energy-dispersive X-ray elemental mapping analysis were used for determining the light-absorption properties, composition, and morphology of all synthesized magnetic catalysts. In addition, the magnetic separation was also achieved by simply applying an external magnetic field. Chapter 3 will discuss and compare the decarboxylation reaction activities of pristine, black, and re-whited TiO2 catalysts. The reactions were carried under the UV, blue, red, green, and white light irradiation. Unfortunately, the reaction was found only working under UV-light irradiation. The best solvent was dioxane which may be due to the proton affinity of the oxygen atom in dioxane molecule, which facilitates the deprotonation of the carboxylic acid. The optimal catalyst amount was found as 10 mg per 5 mL reaction mixture, and the kinetic study shows that the reaction is a pseudo-first order reaction. It is a pity that the performance of black TiO2 catalysts is worse than the pristine and re-whitened TiO2. Chapter 4 will talk about the sol-gel synthesized magnetic catalysts. These catalysts were used for aldehyde-alkyne-amine (A3) coupling reaction. The reaction was tested by light irradiating or traditional heating, but only heating can make the reaction proceed. Results also show that the coupling reaction requires copper to finish. The best solvent was found as toluene and the optimal reaction time is 6 hours at 120 ̊C. Sadly, the reactivity of copper/iron oxide magnetic TiO2 decreases a lot after three reaction cycles because of the copper leaching problem.
, Dayo A. Ayeni
Published: 7 September 2021
Abstract:
The study aims at investigating chemical speciation, bioavailability and risk assessment of some selected metals in soils around refined petroleum depot using the concentrations of the metals as variables to ascertain the impacts of the activities within the petroleum depot. Surface-soils (0–15 cm) were collected from within the premises of Pipelines and Product Marketing Company, Ibadan, Nigeria, while control samples were collected at 200 m away from the study location. Electrical conductivity and pH were measured using a calibrated dual purpose meter, while elemental analysis was done using Atomic absorption spectroscopy analytical technique. The results showed that the soils exhibited low ecological risk; minor enrichment for Mn, moderately severe enrichment for Ni and Co, severe enrichment for Cr and extremely severe enrichment for Pb, Zn and Cd. There was low contamination factor for Pb, Ni, Mn, Cr, Co, and Fe and moderate contamination by Zn and Cd. Geo - accumulation index results indicated unpolluted with Ni, Mn, Cr, Co, and Fe, unpolluted to moderately polluted with Pb and Zn and moderately to strongly polluted with Cd. Inter-element clustering results indicated chemical affinity and/or similar genetic origin among the elements. Speciation analysis suggested that Fe, Co, Cr, Cd, and Ni occurred in the residual fraction; Pb, and Zn in the carbonate fraction, while Mn have its highest percentage in the Fe–Mn oxides fraction. Percentage mobility and bioavailability showed that most of the metals are immobile and non-bioavailable. Study concluded that the oil-impacted soils were contaminated with most of the metals, but with low ecological risk.
Published: 6 September 2021
by MDPI
Applied Sciences, Volume 11; https://doi.org/10.3390/app11178262

Abstract:
A biomonitoring study using terrestrial mosses was performed in the vicinity of an Integrated Iron and Steel plant near the Czech–Polish border. Moss samples were collected in two seasons (June, October) in order to embrace the effect of the heating season on the pollution levels. The contents of metals (Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb, As, Sb and Hg) were determined using the Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Atomic Absorption Spectroscopy (AAS) and contents of N, C, H via elemental analysis. The influence of the proximity of the factory, the heating season and modelled concentrations of particulate matter <10 µm (PM10) on determined concentrations of elements were studied via multivariate statistical methods using clr-transformed data. This approach led to the first-time demonstration that not only the distance from the industrial source but also the sampling season and PM10 concentrations significantly affect the elemental content in mosses; the association of the emissions from the source and the determined concentrations of elements in moss samples were more evident outside the heating season (October). The analyses of transformed data revealed the association of Fe, Cr, V, As and Al with the coarse particles and their dominant spatial distribution depending on the prevailing wind directions. The spatial distribution of Mn, Zn and Cd, which are carried by fine particles, appears to depend more on atmospheric dispersion and long-range transport, and, thus, these metals should be considered weak markers of the pollution load in the close surroundings of an industrial source.
Neean F. Majeed, Maysaa R. Naeemah, Alyaa H. Ali, Sabah N. Mazhir
Iraqi Journal of Science pp 2565-2570; https://doi.org/10.24996/ijs.2021.62.8.9

Abstract:
In the current study, the emission spectra generated from clove were measured under normal atmospheric pressure with different laser energies. Clove is used as a source of essential oil in herbal medicine, in particular as a dynamic analgesic oil in dental and other diseases. For aromatherapy, Antiseptic, antiviral, and antimicrobial agents are also packaged with cloves. Compounds that reduce inflammation tend to battle sore throats, cold, and cough as they display so many advantages. The measured spectrum reveals distinctive lines of clove’s chemical elements. X-ray fluorescent (XRF) and atomic absorption spectrometry (AAS) were used to measure the spectrum generated or absorbed by detecting the presence of various elements and their ratios in the cloves, for different energy the electron temperature varies between 0.043 and 0.073 eV and the number of electron varied between 2.074 and 2.287) x1014 cm-3 for clove.
, H. About, I. Warad, Y. Kerroum, A. Berisha, F. Podvorica, F. Bentiss, G. Kaichouh, B. Lakhrissi,
Published: 23 August 2021
Journal of Molecular Liquids, Volume 342; https://doi.org/10.1016/j.molliq.2021.117333

The publisher has not yet granted permission to display this abstract.
Reyhaneh Toufanian, Xingjian Zhong, Joshua Kays, Alexander Saeboe,
Published: 23 August 2021
Abstract:
The focus on heavy metal-free semiconductor nanocrystals has increased interest in ZnSe semiconductor quantum dots (QDs) over the past decade. Reliable and consistent incorporation of ZnSe cores into core/shell heterostructures or devices requires empirical fit equations correlating the lowest energy electron transition (1S peak) to their size and molar extinction coefficients (ε). While these equations are known and heavily used for CdSe, CdTe, CdS, PbS, etc., they are not well established for ZnSe and are non-existent for ZnSe QDs with diameters < 3.5 nm. In this study, a series of ZnSe QDs with diameters ranging from 2 to 6 nm were characterized with small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), UV-Vis spectroscopy, and microwave plasma atomic emission spectroscopy (MP-AES). SAXS-based size analysis enabled practical inclusion of small particles in the evaluation, and elemental analysis with MP-AES elucidates a non-stoichiometric Zn:Se ratio consistent with zinc-terminated spherical ZnSe QDs. Using these combined results, empirical fit equations correlating QD size with its lowest energy electron transition (i.e., 1S peak position), Zn:Se ratio, and molar extinction coefficients for 1S peak, 1S integral, and high energy wavelengths are reported. Finally, the equations are used to track the evolution of a ZnSe core reaction. These results will enable the consistent and reliable use of ZnSe core particles in complex heterostructures and devices.
, Suleiman A. Itopa, Jwan’An L. Emmanuel, Abdulsalaam O. Abdulazeez, Sambo Ponfa
Asian Journal of Research in Biochemistry pp 22-27; https://doi.org/10.9734/ajrb/2021/v9i130192

Abstract:
Introduction: Terminalia catappa is a large tropical tree in the lead wood tree family, combretacea. This plant is regarded as a medicinal plant and can be used in the treatment of cough, syphilis, hydropsy, rheumatism, and other infections. Aim: This study assessed the nutritional value of Terminalia catappa and the composition of elements present in the plant fruit. Methods: Proximate analysis was carried out according to food chemistry analytical methods and elements were estimated by atomic absorption and flame spectroscopy respectively. Results: Proximate analysis showed that the fruits contained 81.96% moisture content, 1.47% ash, 0.04% crude fat, 1.11% crude protein, 14.05% carbohydrate, and 1.41% crude fibre. The fruits were found to be good sources of minerals. Sodium (2.1±0.01 mg/100 g), potassium (72.5±1.03 mg/100 g), calcium (320±2.00mg/100g), magnesium (20±2.65 mg/100 g), iron (20±3.0 mg/100 g), manganese (2±0.36 mg/100 g), and zinc (8±1.25 mg/100 g). Conclusion: The results revealed the presence of nutrients such as proteins, carbohydrates, crude fats, crude fibre, moisture, and ash in small amounts. And elements analysis shows that sodium, potassium, calcium, magnesium, iron, manganese, and zinc are in appreciable amount. These constituents are therefore responsible for the biochemical values of Terminalia catappa fruits.
, H. Yasumura, Y. Narumi, Y. Kotani, T. Nakamura, H. Nojiri, R. Kainuma
Published: 14 August 2021
Journal of Alloys and Compounds, Volume 890; https://doi.org/10.1016/j.jallcom.2021.161590

The publisher has not yet granted permission to display this abstract.
Alexy P. Freitas, Rémi F. André, Cyprien Poucin, Thi Kim-Chi Le, , ,
The Journal of Physical Chemistry C, Volume 125, pp 17761-17773; https://doi.org/10.1021/acs.jpcc.1c01875

The publisher has not yet granted permission to display this abstract.
Shohel Hossain, , Abhijit Das, A. K. M. Jahirul Hossain Khan, Sohel, Jamiuddin Ahmed, Monirul Islam, Shahadat Hossain, Masudur Rahman, Mst. Luthfun Nesa, et al.
Published: 6 August 2021
Health Science Reports, Volume 4; https://doi.org/10.1002/hsr2.348

Abstract:
Introduction End-stage renal disease (ESRD) is an abnormality where the kidneys are not usually working. This case-control study was planned to determine the extent of serum lipid peroxidation, non-enzymatic antioxidant (vitamin c), and trace elements in 50 patients with ESRD as cases and 50 normal healthy individuals as controls. Methods Determination of lipid peroxidation was carried out by ascertaining concentration of malondialdehyde (MDA) and vitamin C in serum using UV spectrophotometry whereas atomic absorption spectroscopy was used for trace elements estimation. The statistical analysis was conducted via the independent t-test samples and Pearson correlation test. Results The blood serum study has shown substantially higher MDA values than the control level and lowers vitamin C levels in the patient population (P < .001). A negative correlation was found between the vitamin C in serum with BMI and MDA for both patients (r = −0.017 and r = −0.132, respectively) and the control group (r = −0.014 and r = −0.229, respectively) after Pearson's correlation analysis. Regarding trace elements, significantly (P < .001) lower concentrations of zinc, copper, and manganese were found in the patient group than control subjects. Inter-element-relationship established a strong positive harmonization between these studied elements in both the cases of patients and control subjects. Conclusion Our results indicate strong associations of the pathogenesis of ESRD with depleted non-enzymatic antioxidant, increased lipid peroxidation, and inconsistency in trace elements concentration in serum, which may provide a prognostic tool for the treatment of this concerning the disease.
Anand Krishnan
Published: 5 August 2021
Abstract:
Aromatic heterocycles are highly important structural units found in a large number of biologically active natural compounds, pharmaceuticals and catalytic compounds. They have a crucial role in organic syntheses, which results in the generation of high value products. Among heterocycles, those containing nitrogen are the most indispensable structural motifs and are widely used against dreaded diseases such as Malaria, TB, HIV/AIDS and Cancer. The inclusion of highly electronegative atoms such as fluorine in these organic molecules render them very reactive towards proteins. Furthermore these molecules exhibit strong interactions with surfaces of quantum range particles of elemental gold. Various approaches for the synthesis of novel gold nanoparticles linked to potent bioactive molecules are documented and their application as drug delivery systems are of immense value to human health. Also many chemical and physical methods are available for the synthesis of gold, silver and palladium nanoparticles however these methods are usually laborious and produce toxic by-products. The green approach is to use plant extracts to synthesise various size and shape nanoparticles which could be used in biological and catalytic systems. A simple one-pot two component and three component reaction using formyl quinoline, 2-aminothiophenol, thiosemicarbazone and trifluoromethylbenzaldehyde as a reactant to synthesise quinoline, pyridine and pyran based bioactive small molecules; these products are a quinoline type bearing a benzothiazole moiety, quinoline thio semicarbazone ligand, fluorine substituted dihydro pyridine, fluorine substituted dihydropyran and fluorine substituted pyridine derivatives. In total, fifteen compounds were synthesized eleven of which were novel; all compounds were characterized by spectroscopic techniques. In vitro anti-bacterial activities of the synthesized compounds were investigated against a representative panel of pathogenic strains. Compounds 6, 7, 8, 11 and 13 exhibited excellent anti-bacterial activity compared with first line drugs. Potent p53–MDM2 interaction inhibitors 2-thio-1,2-dihydroquinoline-3-carbaldehyde thiosemicarbazone and fluorine substituted new pyridine scaffold were successfully identified by structure-based design. An efficient one-pot four component route to the synthesis of trifluorinated pyrrolophenanthroline and fluoroquinoline pyrrolophenanthrolines was designed. In this reaction 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquid (DMTIL) was used as a reaction medium; no catalyst was required. The structure of the pyrrolophenanthrolines was deduced by IR and NMR analysis. These compounds were studied with Bovine Serum Albumin (BSA) through molecular docking. Hydrophopic, electrostatic and hydrogen bonding interaction played a crucial role in the binding to sub domain of BSA. Interaction studies of DMTIL with BSA by emission, absorption, synchronous fluorescence, circular dichroism (CD) and three dimensional emission (3D) spectroscopic techniques were under taken. The results from emission titration experiments revealed the existence of a strong interaction between BSA and DMTIL ionic liquid. It showed that compounds with lesser number of hydrogen bonds are found to be more active which is attributed to hydrophobic interaction and electrostatic interaction which also played a vital role in DMTIL binding to sub domain IB of BSA. A novel copper-loaded boron nitride nanosheet (Cu/BN) catalyst was prepared and fully characterized. It was used as an efficient and chemoselective catalysts for the synthesis of α-aminophosphonates by the Kabachnik-Fields reaction; twenty one α-aminophosphonates were synthesised. The enhanced catalytic activity and product yield was attributed to the increase of surface acidity. Overall, this methodology offered competitive advantages such as recyclability of the catalyst without further purification or without using additives or cofactors, low catalyst loading, broad substrate applicability and high yields. The application of this new nanocatalyst in organic synthesis will provide a novel pathway for the synthesis of pharmaceutically important compounds. Gold nanoparticle surfaces were modified with self-assembled monolayers of important thiol and disulfide bioactive molecules since considerable interest is due to their potential application as anti-cancer agents. Herein, a carbazole was conjugated to lipoic acid by using an amide coupling catalyst HBTU and DIEA reaction. The structure of the carbazole thio octanic acid (CTN) was identified by IR and NMR. CTN was attached to the gold nanoparticles surface and the capping behaviour was characterized by UV-vis spectroscopy, TEM, DLS and FTIR. The cytotoxicity of CTNAuNPs on A549 cell lines was determined using the MTT assay. The results suggest CTN and CTNAuNPs possess anti-proliferative properties in the cancerous A549 cells. Furthermore a dual thiol ligand was synthesized by using equimolar 4-aminothiophenol (4-ATP) and amino oxadiazole thiol (AXT). This dual ligand was attached to the gold nanoparticles surface (DTAu) and the capping behaviour was characterized by UV-vis spectroscopy, TEM, DLS and FTIR. The cytotoxicity of DTAu on A549 cell lines was determined using the MTT assay. The results suggest dual ligands (4-ATP, AXT) and DTAu possess anti-proliferative properties in the cancerous A549 cells. South African indigenous plants and agroforestry waste were also used in the synthesis of silver, gold and palladium nanoparticles (NPs). Green protocols such as the use of environmentally benign solvents and non-hazardous reagents were an added advantage to physical and chemical means. Furthermore these reactions were rapid and the size and shape of the NPs could be manipulated by choosing the correct medium. The formulation of natural medicinal compounds capped onto NPs was assessed for their...
Saifullah Jamali, M. Aslam Khoso, M. Haider Zaman, , Waseem Ahmed Bhutto, Aatif Abbas, Riaz Hussain Mari, M. Siddique Kalhoro,
Published: 19 July 2021
Physica B: Condensed Matter, Volume 620; https://doi.org/10.1016/j.physb.2021.413278

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, Christine Cheesley
International Research Journal of Pure and Applied Chemistry pp 54-59; https://doi.org/10.9734/irjpac/2021/v22i530409

Abstract:
Excess trace metal contamination in vegetables is a growing concern globally. Plants can be contaminated by trace metals, and it is important to understand the degree of contamination and the inherent risk. Vegetables are a staple in human diets, thus knowing the level of concentration of these metals within the diet is increasingly important. This project is designed to assess levels of trace metals in vegetables using Atomic Absorption Spectroscopy. Atomic absorption spectroscopy (AAS) is an analytical technique that determines unknown concentrations of elements using absorption of light from the desired elements with the aid of the working calibration curve obtained from the series of standards. Tests were done on three different commonly vegetable available in the UK to identify whether levels of trace metals fall within safe levels for human consumption. The vegetables selected were carrots, potatoes, and tomatoes. The concentration within organic vegetables did not significantly differ from the non-organic ones, though the results show, in some cases higher concentration of chromium in the potato and carrot peel. This is worthy of note from a health and nutrition perspective especially for those people that have a deficiency of these trace metals in their body or conversely wanted to manage their intake. The mean concentrations of these metals are in decreasing order of >Pb>Cr in most vegetables but in some Cr>Pb. The good thing is that the concentrations of these metals in vegetables purchased in the UK all fall below the maximum limits set by WHO/FAO and are thus considered safe for human consumption.
, Johannes Schaumlöffel, Andrea Lösch, Annelies De Cuyper,
ACS Applied Materials & Interfaces, Volume 13, pp 33091-33101; https://doi.org/10.1021/acsami.1c08267

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G.C. Gomes, , F.F. Borghi, G.H. Cavalcanti, C.M.S. Martins, V. Palleschi, A. Mello
Spectrochimica Acta Part B: Atomic Spectroscopy, Volume 184; https://doi.org/10.1016/j.sab.2021.106250

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Akhilesh C. Joshi, Mainak Roy, , Raman K. Mishra, Sher Singh Meena, Ravi Kumar, Dibyendu Bhattacharyya, Rajath Alexander, C.P. Kaushik, A.K. Tyagi
Journal of Non-Crystalline Solids, Volume 570; https://doi.org/10.1016/j.jnoncrysol.2021.121016

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Dara Fitzpatrick, Jeremy D. Glennon
Published: 3 July 2021
Encyclopedia of Dairy Sciences pp 309-313; https://doi.org/10.1016/b978-0-12-818766-1.00390-1

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Published: 2 July 2021
Nanomagnetic Materials pp 199-303; https://doi.org/10.1016/b978-0-12-822349-9.00010-9

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Yaddala Thanusha, A.S. Vickram
Alinteri Journal of Agriculture Sciences, Volume 36, pp 692-697; https://doi.org/10.47059/alinteri/v36i1/ajas21097

Abstract:
Aim: The major aim of this study is to compare Zinc (Zn) concentration present in human seminal plasma of asthenospermia (motility issues) and normospermia semen samples for identification of clinical relevance. Materials and Methods: Semen samples of normospermia (N=75), asthenospermia (N=75) were collected and semen analysis report has been done by standard world health organization protocol. Zn concentration was evaluated by using atomic absorption spectroscopy (AAS) for both the groups by using standard protocol. Results: Independent sample T-test on fertile and infertile men (asthenospermia and normospermia group) reveals that the zinc concentration is statistically insignificant (P=0.367). Zinc concentration was found to be high in normospermia (mean 2.5 mg/ml) over asthenospermia (mean 0.90 mg/ml) samples. Conclusion: Zn being an essential element for normal functioning for fertilization, its absence or less concentration may lead to infertility. We found high concentration of Zn in normospermia which reflects normal conditions for fertilization and less concentration in asthenospermia reflecting infertile conditions.
M. Kumar, V. K. Verma,
Surface and Interface Analysis, Volume 53, pp 808-813; https://doi.org/10.1002/sia.6982

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Published: 18 June 2021
by MDPI
Materials, Volume 14; https://doi.org/10.3390/ma14123386

Abstract:
New benzo[h]quinolin-10-ol derivatives with one or two 2-cyanoacrylic acid units were synthesized with a good yield in a one-step condensation reaction. Chemical structure and purity were confirmed using NMR spectroscopy and elemental analysis, respectively. The investigation of their thermal, electrochemical and optical properties was carried out based on differential scanning calorimetry, cyclic voltammetry, electronic absorption and photoluminescence measurements. The analysis of the optical, electrochemical and properties was supported by density functional theory studies. The synthesized molecules were applied in dye-sensitized solar cells as sensitizers and co-sensitizers with commercial N719. The thickness and surface morphology of prepared photoanodes was studied using optical, scanning electron and atomic force microscopes. Due to the utilization of benzo[h]quinolin-10-ol derivatives as co-sensitizers, the better photovoltaic performance of fabricated devices compared to a reference cell based on a neat N719 was demonstrated. Additionally, the effect of co-adsorbent chemical structure (cholic acid, deoxycholic acid and chenodeoxycholic acid) on DSSC efficiency was explained based on the density functional theory.
Mohamad Ismail Mohamad Isa, Siti Maizatul Ameera Azhar, Nazikussabah Zaharudin, Ahmad Salihin Samsudin,
Published: 17 June 2021
Macromolecular Symposia, Volume 397; https://doi.org/10.1002/masy.202000240

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Sh. Nuguyeva, E. Mammadov
Bulletin of Science and Practice, Volume 7, pp 60-66; https://doi.org/10.33619/2414-2948/67/08

Abstract:
The increasing content of heavy metals in soil and atmospheric air can lead to serious consequences in the final link of which a person is. To determine heavy metals in atmospheric deposition, the method of biomonitoring of mosses was used. Joint Institute for Nuclear Research scientists started the implementation of the mosses biomonitoring methodology in Azerbaijan 2015. In total, the concentration was determined for 44 elements. Determinations were performed using instrumental analysis of Epithermal Neutron Activation and Atomic Absorption Spectroscopy in 85 moss samples. The species of moss used in the work was Pleurosium schreberi. Based on the analysis results, the most contaminated areas are identified.
Ambreen Aziz, Urooj Haroon, Kausar Yasmeen, M Hashim Zuberi, Khalid Hassan, Maryam Hassan
International Journal of Economic and Environmental Geology, Volume 12, pp 14-19; https://doi.org/10.46660/ijeeg.vol12.iss1.2021.552

Abstract:
Use of municipal waste water (both treated and untreated) has now become a common practice in urban and peri-urban areas. Mostly vegetables in urban cities like Karachi are being irrigated by sewerage water. In this study a comparison of sewage and fresh water-irrigated vegetables has been made with respect to trace metals. Among commonly used vegetables, green onion, cabbage, pumpkin, eggplant, bird’s eye chili and okra were selected. Two sets of these vegetables were collected, one from local farm where irrigation was done with well water and other set of samples was collected from Malir, Karachi where irrigation was done with waste water. Samples were analyzed for heavy metals i.e. K, Na, Pb, Zn, Cu, Cd, Fe, and As by Atomic Absorption Spectroscopy. It showed that both sets of samples were found to contain metal concentrations beyond the limits set by WHO/EU. Apart from tomato, the concentration of only Cd was near the standard value for both sets. Similar results were obtained for K except for pumpkin in which the concentration for waste water irrigated samples was fairly high. Amount of Cu and Fe were moderately higher than the standard in both samples. Arsenic in all the samples was considerably high while maximum concentration was obtained for Pd against the limits. These findings suggest waste water irrigated vegetables pose high risk to human health. The concentrations of As and Pb were high in fresh water samples possibly, the well water may contain metals, therefore it is important to know the source.
, Ahmad Khan, Mohammad Zameer Khan, Fayyaz Hussain, Zafar Islam, Muhammad Asad Hameed
Pakistan Journal of Agricultural Research, Volume 34; https://doi.org/10.17582/journal.pjar/2021/34.2.472.478

Abstract:
| Post-harvest crop residues and coal have potential to be used for the extraction of humic substance, a macroorganic molecule. The humic substances were extracted quantified and characterized using techniques such as spectrophotometer, High Performance Liquid chromatography, Fourier transform infrared spectroscopy and atomic absorption spectrophotometer. The analysis showed the presence of hydrophobic and hydrophilic sites. The Fourier infrared spectroscopy analysis showed spectrum bends at different wavenumbers while elemental analysis show existence of different macro and micro nutrients which can be used to supplement the plant needs for nutrients by incorporation of humic substances along with commercial inorganic fertilizers. Though findings in this study showed KOH as cost effective extractant vis a vis NaOH. However, further characterization could not confirm it. The presence of hydrophobic and hydrophilic nature of sites could be utilized to develop slow release plant nutrients based on humic substances.
Deborah J. Myers, A. Jeremy Kropf, Evan C. Wegener, Jaehyung Park
ECS Meeting Abstracts, pp 1962-1962; https://doi.org/10.1149/ma2021-01491962mtgabs

Abstract:
With wavelengths on the order of atomic dimensions and the ability to penetrate through low atomic number materials (e.g., Nafion® and carbon), hard X-rays, particularly those arising from synchrotron sources with high brilliance, are ideal for the atomic-level characterization of polymer electrolyte fuel cell (PEFC) catalysts in situ, in aqueous environments that mimic PEFC conditions, and operando, in the membrane-electrode assembly (MEA) environment. Two particularly valuable X-ray techniques for this purpose are X-ray absorption spectroscopy (XAS) and small angle X-ray scattering (SAXS) or anomalous SAXS (ASAXS), which allows discrimination of scattering from the absorbing element. Analysis of the X-ray spectrum near the absorption edge of interest (i.e., the near edge or XANES region) provides information on the oxidation state and electronic structure (e.g., d-band vacancy) of the material, properties that have been associated with catalyst activity. The extended region of the XAS spectrum (EXAFS) yields information on the atomic structure and coordination environment of the absorbing element (i.e., number and identity of nearest neighbors and distances between atoms). Unlike X-ray diffraction, XAS is particularly useful for characterization of platinum nanoparticle catalysts and of single-site platinum-group metal-free catalysts, such as Fe-N-C catalysts. However, EXAFS can be limited in the information it can provide regarding the bonding geometries, but absorption in the pre-edge region, which is sensitive to bonding geometry, can provide this essential information. SAXS and ASAXS are well-established techniques for probing particle sizes and particle size distributions on the nanometer level. While not as widely-used in the fuel cell community as XAS, SAXS and ASAXS are well-suited to examining nanoparticle fuel cell catalysts, which typically have particle diameters of 2-5 nm.This presentation will discuss the information that can be obtained from X-ray spectroscopy and scattering techniques and provide examples of application of these techniques to the study of platinum and platinum alloy nanoparticle catalysts and atomically-dispersed Fe-N-C and Co-N-C PEFC cathode catalysts. The utility of using a combination of XAS and ASAXS to study platinum alloy catalyst degradation and of the combination of information from XANES, EXAFS, and XAS pre-edge data to an Fe-N-C catalyst will be presented.Acknowledgements:This research was supported by the U.S. Department of Energy (DOE), Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office (HFTO), through the Electrocatalysis Consortium (ElectroCat). This research used resources of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. The authors thank Hoon Chung of Los Alamos National Laboratory for providing the Fe-N-C catalyst and Johnson Matthey Fuel Cells for providing the Pt and PtCo catalysts. This work was conducted at Argonne National Laboratory, a U.S. DOE Office of Science Laboratory operated for the U.S. DOE by UChicago Argonne, LLC, under Contract DE-AC02-06CH11357.
James W. Robinson, Eileen M. Skelly Frame, George M. Frame
Instrumental Analytical Chemistry pp 303-352; https://doi.org/10.1201/b21879-6

Abstract:
The basis of atomic absorption spectrometry (AAS) is the absorption of discrete wavelengths of light by ground state, gas phase free atoms. Free atoms in the gas phase are formed from the sample by an “atomizer” at high temperatures. AAS was developed in the 1950s by Alan Walsh and rapidly became a widely used analytical tool. AAS is an elemental analysis technique capable of providing quantitative information on ∼70 elements in almost any type of sample. As an elemental analysis technique, it has the significant advantage in many cases (but not all) of being practically independent of the chemical form of the element in the sample. A determination of cadmium in a water sample is a determination of the total cadmium concentration. It does not matter whether the cadmium exists as the chloride, sulfate, or nitrate, or even if it exists as a complex or an organometallic compound, if the proper analysis conditions are used. Concentrations as low as part per trillion (ppt) levels of some elements in solution can be determined and AAS is used routinely to determine ppb and ppm concentrations of most metal elements. Another principal advantage is that a given element can be determined in the presence of other elements, which do not interfere by absorption of the analyte wavelength. Therefore, it is not necessary to separate the analyte from the rest of the sample (the matrix). This results in rapid analysis times and eliminates some sources of error. This is not to say that AAS measurements are completely free from interferences; both chemical and spectral interferences do occur and must be compensated for, as will be discussed. The major disadvantages of AAS are that no information is obtained on the chemical form of the analyte (no “speciation”) and that often only one element can be determined at a time. This last disadvantage makes AAS of very limited use for qualitative analysis. AAS is used almost exclusively for quantitative analysis of elements, hence the use of the term “spectrometry” in the name of the technique instead of “spectroscopy”.
Atittaya Meenongwa, Rosa F. Brissos, Chaiyaporn Soikum, Prapansak Chaveerach, Yanee Trongpanich,
Published: 13 May 2021
Journal of Molecular Structure, Volume 1241; https://doi.org/10.1016/j.molstruc.2021.130645

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Reagan R.D. Weeks, , Yu Zhang, Sivanandan S. Harilal, R. Jason Jones
Spectrochimica Acta Part B: Atomic Spectroscopy, Volume 181; https://doi.org/10.1016/j.sab.2021.106199

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