Elemental Analysis Research Articles

Investigation on novel chitin and chitosan from dung beetle Heteronitis castelnaui (Harold, 1865) and its potential application for organic dyes removal from aqueous solution

Chitosan, a natural polysaccharide, has attracted considerable attention as an environmentally friendly and highly efficient adsorbent for dye removal. It is usually produced by deacetylation or partial deacetylation of chitin. However, conventional sources of chitin and chitosan are limited, prompting the need for alternative sources with improved adsorption capabilities. Herein, this study focuses on exploring a novel chitin and chitosan source derived from the dung beetle and evaluates its potential for organic dye removal from aqueous solutions. The research involves the extraction and characterization of chitin and chitosan from dung beetle Heteronitis castelnaui (Harold, 1865) using various analytical techniques, including SEM, FT-IR, TGA, XRD, NMR, deacetylation degree and elemental analysis. The chitosan obtained was used for the formation of hydrogels with sodium alginate via cross-linking with calcium chloride. And then the prepared hydrogels were evaluated for its adsorption capacity through batch adsorption experiments using methylene blue as a model pollutant. The adsorption capacity for methylene blue was 1294.3 mg/g at room temperature with solution pH = 12, MB concentration of 1800 mg/L. Furthermore, the kinetics of the adsorption process were analyzed using pseudo-first-order and pseudo-second-order models to understand the rate of adsorption. The maximum adsorption capacities were determined using Langmuir and Freundlich isotherm models. This study provides valuable insights for the development of sustainable dye adsorption technologies, specifically investigating a novel chitosan source derived from the dung beetle.

Chemical characterization of heat‐treated kraft lignin after fractionation with organic solvents and pH effect

AbstractLignin, the main source of renewable aromatics, has a complex structure, high polydispersity, and low reactivity, which hinders its large‐scale use. This study aims to improve lignin reactivity through heat treatment combined with fractionation by organic solvents or the pH effect. Heat treatment of commercial hardwood black liquor was performed at 225 °C for 150 min. The samples were then fractionated either by using organic solvents (ethyl acetate, ethanol, methanol, and acetone) or by lowering pH using hydrochloric acid (HCl) (pH values 1, 3, 5, 7, and 9). The fractionation was carried out in one step and in sequential mode. The fractionated samples were characterized chemically by the content of acid‐soluble and acid‐insoluble lignin, carbohydrates, ash, inorganic compounds (metals), elemental analysis, and by pyrolysis‐gas chromatography–mass spectrometry (Py‐GC–MS). The highest mass yields were obtained using the one‐step mode for both fractionations, with yields as high as 53.3% for organic solvents and 47.8% for the pH effect. Solvent fractionation reduced ash content by up to 75.4% and increased calorific value, carbon content, and total lignin content. Fractionation by pH effect showed an ash reduction of up to 55.9% and an increase in calorific value and carbon content of up to 8.7 MJ kg−1 and 49.7%, respectively. The Hansen solubility parameters were also calculated to address lignin's solubility in each of the tested solvents. These findings indicate that combining heat treatment and fractionation techniques improves lignin's chemical properties significantly, making it a more viable raw material for industrial use. This approach supports the circular economy by transforming lignin into a high‐value product, thereby promoting sustainable and efficient resource utilization across industries.

Preparation and characterizations of metal-based complexes derived from the reaction of trizma base with Mg(II), Ca(II), and Ba(II) ions

Trizma base is a small organic compound that possesses one amino group (-NH2) and three hydroxyl groups (-OH). Three products of trizma base as a ligand were prepared from the reaction of Mg(II), Ca(II), and Ba(II) ions with the ligand at a temperature of 65 °C and stoichiometry of 1:1 (ligand to metal ion). The trizma ligand was referred to as Tris, and its complexes with Mg(II), Ca(II), and Ba(II) ions were referred to as Product 1, Product 2, and Product 3, respectively. After the preparation of the products, they were characterized by several analytical methods, including spectroscopies [Fourier-transform infrared (FT-IR) and ultraviolet/visible (UV-visible)], thermogravimetry (TG), elemental analyses, X-ray diffraction (XRD), and scanning electron microscope with environmental mode (ESEM). Analytical results suggested that Tris ligand captured the investigated metal ions using the amino group (-NH2) and one hydroxyl group (-OH) forming complexes with general composition of [MgTris(H2O)4]·Cl2·2H2O (Product 1), [CaTris(H2O)4]·Cl2·2H2O (Product 2), [BaTris(H2O)4]·Cl2·H2O (Product 3). The corresponding gross formulas for these products were C4H23NO9MgCl2 (324.34), C4H23NO9CaCl2 (340.11), and C4H21NO8BaCl2 (419.37 g/mol), respectively. SEM micrographs captured at high levels of magnification (×100,000) clearly illustrate variations in the morphology of products 1, 2, and 3. KEY WORDS: Trizma base, Spectral analysis, Thermogravimetry, SEM micrographs Bull. Chem. Soc. Ethiop. 2024, 38(6), 1791-1801. DOI: https://dx.doi.org/10.4314/bcse.v38i6.22

Preparation of new compounds with anticancer properties via the reaction of Kryptofix 5 with two organic acceptors

The new designed complexes via CT interaction between kryptofix 5 and two organic acceptors to introduce basic data that can be used to assessment of crown ether and tested the final complexes against cancer cells. This target was achieved by synthesis of a new CT- complexes of kryptofix 5 as a type of mixed nitrogen–oxygen crown ethers with π-acceptors as (2 hydroxy-3.5-dinitrobenzoic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone). These obtained complexes were structurally characterized in both solid and liquid state via various chemical methods as elemental analysis, FT-IR, NMR, and UV–Visible spectroscopy, thermal degradation and physical properties were calculated. Finally, the CT complex was also tested for its anticancer activity against two human cancer cell lines; colon cancer CaCo2 and liver cancer cell line (hepG2). KEY WORDS: Anticancer, Kryptofix 5, HDNS, DDQ, Spectroscopy Bull. Chem. Soc. Ethiop. 2024, 38(6), 1639-1651. DOI: https://dx.doi.org/10.4314/bcse.v38i6.11

Investigation of the Effects of Waste Olive Pomace on Vermicompost

The effects of olive pomace on the degradation of organic matter were investigated via vermicomposting. Biomass consisting of eggshell, cabbage, banana peel, napkin, nutshell, cattle manure, and soil was amended with varying amounts of olive pomace (0, 15, 30, 37.5%). These four mixtures, with a total of 2000g, were fed to 170 Eisenia fetida earthworms per mixture. Nitrogen adsorption-desorption, FT-IR, and elemental analyses analyzed samples collected from biomass at the end of 45 days. Results were evaluated to determine the effect of olive pomace on organic matter degradation and earthworm vitality. Nitrogen adsorption-desorption isotherms of feedstock revealed a decrease in void volumes, implying the formation of a compact structure with olive pomace addition. Vermicomposting of biomass enhanced biomass’s compactness, further validated by decreases in BET surface areas, pore sizes, and pore volumes. The 31% increase of earthworm biomass in the presence of 37.5% olive pomace implied an affinity of Eisenia fetida towards olive pomace. This finding was further validated by FT-IR peaks obtained at 2850 and 2923 cm-1, showing increased biomass aromaticity due to the degradation of readily biodegradable aliphatic structure introduced by olive pomace. Ongoing organic matter degradation could be observed with the decrease of C/N ratios in the presence of olive pomace as high as 15%. However, a further increase in olive pomace increased the C/N ratio, which was explained by the increase in total nitrogen values during vermicomposting. Elemental analyses evaluated regarding C/N, O/C, and H/C ratios also indicated increased earthworm mobility with increasing olive pomace in the feedstock. The results obtained in the study were interpreted to introduce olive pomace as a preferable nutrition source for earthworms, which was the highlight of the present study

Design, characterizations, DFT, molecular docking and antibacterial studies of some complexes derived from 4-aminpantipyrine with glycine amino acid and ligand

The synthesis of the heterocyclic ligand (LK) involved the combination of 4-amino antipyrine, 4-nitroacetophenone, and glycine. A new series of transition metal complexes of Ni(II), Co(II), Cu(II), and Zn(II) have been synthesized from the Schiff base (LK). It was characterized by micro elemental analysis, FT-IR, UV-Vis, and 1H-NMR spectroscopy. The prepared complexes were characterized using (CHN) analysis, flame atomic absorption, as well as conductivity measurements and magnetic susceptibility. From the obtained data, the octahedral structure was suggested for all complexes. The ligand showed tridentate nature by binding to metal ions through the N atom of antipyrine and the N,O atom of glycine. The exhibited excellent electrolytic properties, except for the Cu(II) and Zn(II) complex which exhibited non-electrolytic behavior. Theoretical calculations with DFT were conducted for all complexes. The antibacterial activity of the ligand and its complexes against (S. aureus, B. subtilis) was evaluated through the disc diffusion method. Additionally, molecular docking analysis was conducted to gain more insights into the ligand's binding energy and interaction with the S. aureus receptor. KEY WORDS: 4-Amino antipyrine, Heterocyclic ligand, Glycine, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(6), 1609-1624. DOI: https://dx.doi.org/10.4314/bcse.v38i6.9

A Comprehensive Evaluation of Electrochemical Performance of Aluminum Hybrid Nanocomposites Reinforced with Alumina (Al2O3) and Graphene Oxide (GO)

The electrochemical performance of in-house developed, spark plasma-sintered, Aluminum metal–matrix composites (MMCs) was evaluated using different electrochemical techniques. X-ray diffraction (XRD) and Raman spectra were used to characterize the nanocomposites along with FE-SEM and EDS for morphological, structural, and elemental analysis, respectively. The highest charge transfer resistance (Rct), lowest corrosion current density, lowest electrochemical potential noise (EPN), and electrochemical current noise (ECN) were observed for GO-reinforced Al-MMC. The addition of honeycomb-like structure in the Al matrix assisted in blocking the diffusion of Cl− or SO4−2. However, poor wettability in between Al matrix and Al2O3 reinforcement resulted in the formation of porous interface regions, leading to a degradation in the corrosion resistance of the composite. Post-corrosion surface analysis by optical profilometer indicated that, unlike its counterparts, the lowest surface roughness (Ra) was provided by GO-reinforced MMC.

Investigation of the crystal structure, spectral properties, and interactions of N-(R-nitrophenylsulfonamido)benzoic acids with human serum albumin

This study introduced the synthesis of two novel compounds in the N-(R-nitrophenylsulfonamido)benzoic acids (NO2-SBA), designated as HL6 and HL8. Detailed structural information for HL6 and HL8 was acquired through the employment of various characterization techniques such as single-crystal and powder X-ray diffraction, FT-IR spectroscopy, 1H and 13C NMR spectroscopy, and elemental analysis. X-ray diffraction and Hirshfield surface analysis provides a comparative analysis of hydrogen bonding in HL6·H2O and HL8, revealing significant differences in their interaction patterns and resulting crystal structures. Although both molecules possess the same number of hydrogen bond donors and acceptors, the nature of these interactions and their orientations lead to distinct packing arrangements. In HL6·H₂O, the presence of water molecules introduces additional hydrogen bonding possibilities, which are absent in HL8, significantly affecting the overall structure. Additionally, interactions of all nine compounds in the NO2-SBA series [categorized as o-ABA: HL1–HL3, m-ABA: HL4–HL6, and p-ABA: HL7–HL9] with human serum albumin (HSA) were investigated to understand how structural characteristics influence binding mechanisms and affinity. Fluorescence spectroscopy was employed to further examine these interactions, providing a better understanding of their pharmacological properties. The compounds exhibited moderate affinity to HSA, with the o-ABA series displaying a binding constant (Kb) ten times stronger than the other series, underscoring the significant role of the N,R groups in binding interactions.

Spectral studies of a selenium(IV) vitamin B3 compounds prepared in the form of nanometer using simple chemical reactions to further use as antioxidant in the preparation of drugs

The current study dealt with selenium metal ion complexes with mixed ligands, consisting of nicotinamide (vitamin B3) as the first ligand, and amino acids such as (histidine, tryptophan, and tyrosine) as the second ligand. It was synthesized in (1:1:1) (selenium: vitamin: amino acid) in molar ratio. By using different characterization techniques such as elemental analysis, the conductance, FTIR, XRD, UV-Vis, TG/DTG, 1H-NMR, XRD, SEM, TEM analyses, the chemical structures and the morphological properties of the synthesized complexes were checked and discussed. The nicotinamide was coordinated as monodentate ligand via the nitrogen of pyridine ring but all amino acids as a secondary ligand coordinated as bidentate through oxygen of carboxylic group and nitrogen of amino group. The complexes demonstrate antioxidant activity with potent scavenging property, the synthesized in the form of nanometer give great importance in increasing efficiency of absorption of human cells to selenium giving the highest efficiency of medical product. All complexes in this study were evaluated for their anticancer effect towards HepG2 and A2780 cell lines. From these data the complex (Se/Nia/ Tyr) can be used as antitumor agents. KEY WORDS: Selenium, Amino acids, Vitamin B3, Mixed ligand, Complexes, Antioxidant Bull. Chem. Soc. Ethiop. 2024, 38(6), 1759-1774. DOI: https://dx.doi.org/10.4314/bcse.v38i6.20

Isolation and Electronic Structures of Lanthanide(II) Bis(trimethylsilyl)phosphide Complexes.

While lanthanide (Ln) silylamide chemistry is mature, the corresponding silylphosphide chemistry is underdeveloped, with [Sm{P(SiMe3)2}{μ-P(SiMe3)2}3Sm(THF)3] being the sole example of a structurally authenticated Ln(II) silylphosphide complex. Here, we expand the Ln(II) {P(SiMe3)2} chemistry through the synthesis and characterization of nine complexes. The dinuclear "ate" salt-occluded complexes [{Ln[P(SiMe3)2]3(THF)}2(μ-I)K3(THF)] (1-Ln; Ln = Sm, Eu) and polymeric "ate" complex [KYb{P(SiMe3)2}3{μ-K[P(SiMe3)2]}2]∞ (2-Yb) were prepared by the respective salt metathesis reactions of parent [LnI2(THF)2] (Ln = Sm, Eu, Yb) with 2 or 3 equiv of K{P(SiMe3)2} in diethyl ether. The separate treatment of these complexes with either pyridine or 18-crown-6 led to the formation of the mononuclear solvated adducts trans-[Ln{P(SiMe3)2}2(py)4] (3-Ln; Ln = Sm, Eu, Yb) and [Ln{P(SiMe3)2}2(18-crown-6)] (4-Ln; Ln = Sm, Eu, Yb), with concomitant loss of K{P(SiMe3)2}. The complexes were characterized by a combination of NMR, electron paramagnetic resonance (EPR), attenuated total reflectance infrared (ATR-IR), electronic absorption and emission spectroscopies, elemental analysis, SQUID magnetometry, and single crystal X-ray diffraction. We find that these complexes contrast with those of related Ln(II) bis(silyl)amide complexes due to differences in ligand donor atom hardness and ligand steric requirements from Ln-P bonds being longer than Ln-N bonds. This leads to higher coordination numbers, shorter luminescence lifetimes, and smaller easy-axis magnetic anisotropy parameters.

Pyridine Derivatives as Insecticides: Part 6. Design, Synthesis, Molecular Docking, and Insecticidal Activity of 3-(Substituted)methylthio-5,6,7,8-tetrahydroisoquinoline-4-carbonitriles Toward Aphis gossypii (Glover, 1887).

Three new series of 3-(substituted)methylthio-4-cyano-5,6,7,8-tetrahydroisoquinolines were designed and synthesized starting from readily available materials, 7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(4-pyridyl, 3-pyridyl, phenyl, 4-methoxyphenyl, or 4-chlorophenyl)-5,6,7,8-tetrahydrosoquinoline-3(2H)-thiones 2a-e in high yields and very pure states. Thus, compounds 2a-e were reacted with some chloro reagents, namely, N-aryl-2-chloroacetamides 3a-f and N-(naphthalen-2-yl)-2-chloroacetamide (3g) under mild basic conditions to give the first two series of the target compounds, 3-(N-aryl)carbamoylmethylthio-5,6,7,8-tetrahydroisoquinoline-4-carbonitriles 4a-l and 5a-e, respectively. Reaction of compounds 2d,e with ethyl chloroacetate under the same conditions gave the other series, 3-ethoxycarbonyl-methylthio-5,6,7,8-tetrahydroisoquinoline-4-carbonitriles 6d,e. Structural formulas of all of the new compounds were elucidated and confirmed by elemental and spectral analyses. The insecticidal activity of all synthesized 5,6,7,8-tetrahydrosoquinolines toward the nymphs and adults of Aphis gossypii were screened. The results revealed the promising insecticidal activity of some tested compounds. Moreover, the structure-activity relationships as well as molecular docking of some representative compounds were evaluated.

Novel Cu(II) and Zn(II) Nanocomplexes Based on 5,6‐Diphenyl‐1,2,4‐Triazine: Preparation, Spectroscopic, TD‐DFT Calculations, Molecular Docking and Solvatochromic Studies

ABSTRACTThe reaction between 2‐hydroxy‐1‐naphthaldehyde and 3‐hydrazino‐5,6‐diphenyl‐1,2,4‐triazine produced a novel hydrazone ligand (DTHMN), which reacted with Cu(II) and Zn(II) metal ion in molar ratio 1:1, giving octahedral Cu(II)‐DTHMN and tetrahedral Zn(II)‐DTHMN nanosized complexes. The structural geometries have been elucidated on the basis of elemental analysis, nuclear magnetic resonance, infrared, electronic, and electron spin resonance spectra, and magnetic and molar conductance measurements as well as x‐ray diffraction and thermal analysis. TEM analysis showed that Zn(II)‐DTHMN complex has nano‐rode morphology shape. On the other hand, Cu(II)‐DTHMN has sphere shape within nanodomain. The DTHMN ligand exhibits ONN chelating sites through N‐triazine ring, azomethine nitrogen, and deprotonated OH group, forming the mononuclear metal complexes. The synthesized compounds showed a distinct solvatochromic behavior in different polar solvents. A bathochromic alteration is observed when moving from less to high polar solvents, indicating strong solute–solvent interactions accompanied by intramolecular charge transfer (ICT). The ground and excited state dipole moments of these compounds were determined experimentally by solvatochromic shift method using Bilot–Kawski, Lippert–Mataga, Bakhshiev, and Kawski–Chamma–Viallet functions and a microscopic Reichardt's solvent polarity parameter (ETN). The dipole moment is increased significantly upon excitation referring to stabilizing the excited species includes n–π* transition by polarity of solvent. The experimental results are generally consistent with those values obtained by B3LYP/GENECP method at 6‐311G(d,p) basis set for C, H, N, and O atoms and SDD (Stuttgart/Dresden) basis set for the metal atoms. The compounds were tested for antimicrobial efficiency against Gram‐positive bacteria, Gram‐negative bacteria, and fungus strain. Finally, molecular docking was used to study the interactions between donors (the current compounds) and receptors FabH–CoA complex (PDB code: 1HNJ).

Geochronology and Geochemical Characteristics of Granitoids in the Lesser Xing’an–Zhangguangcai Range: Petrogenesis and Implications for the Early Jurassic Tectonic Evolution of the Mudanjiang Ocean

This article focuses on zircon U-Pb isotope dating and a whole-rock elemental analysis of granodiorites, monzonitic granites, granodioritic porphyries, and alkali feldspar granites in the Yangmugang area of the Lesser Xing’an–Zhangguangcai Range. The zircon U-Pb isotope-dating results revealed that these granitic rocks formed during the late Early Jurassic period (182.9–177.2 Ma). Their geochemical characteristics and zircon saturation temperatures suggest that the granodiorites are moderately differentiated I-type granites and the monzonitic granite, granodioritic porphyries, and alkali feldspar granites are highly differentiated I-type granites. The degree of magma differentiation progressively increased from granodiorites to alkali feldspar granites. By combining the regional Nd and Hf isotope compositions, it was inferred that the magma source involved the melting of lower crustal material from the Mesoproterozoic to the Neoproterozoic eras. By integrating these findings with contemporaneous intrusive rock spatial variations, it was indicated that the late Early Jurassic granitoids in the Lesser Xing’an–Zhangguangcai Range formed within an extensional tectonic setting after the collision and closure of the Songnen–Zhangguangcai Range and Jiamusi blocks. Additionally, this study constrains the closure of the Mudanjiang Ocean to the late Early Jurassic period (177.2 Ma).

Green synthesis of copper oxide nanoparticles using Ficus racemosa leaf extract and investigation of its antibacterial properties

ABSTRACT The present work reports a one-pot green synthesis of copper oxide nanoparticles (CuO NPs) using Ficus racemosa leaf extract via a green chemistry approach without using any harsh chemical reagents. The crystalline and single-phase CuO NPs were analysed via XRD. DLS revealed the average particle size distribution, and zeta potential was used for the evaluation of surface charge. Optical properties were determined at 530 nm through UV–Vis spectroscopy with a broad peak in the range from 500 to 590 nm. Different functional groups in the leaf extract containing flavonoids and polyphenols as reducing agents responsible for the synthesis of CuO NPs were verified through FTIR. The FESEM images revealed the average particle size in the range from 30 to 300 nm with a spherical morphology, and EDS was used for the quantitative elemental analysis. The strong bacterial inhibition tendency of CuO NPs against 12 bacterial strains including Bacillus cereus, Campylobacter jejuni, Bacillus subtilis, Clostridium perfringens, Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Vibrio cholerae, Shigella dysenteriae, Listeria monocytogenes, Helicobacter pylori, and Salmonella typhi was observed with MIC values between 60 and 1000 µg/mL. The findings suggest that the synthesis of CuO NPs via green chemistry can serve as a potential substitute for traditional multi-step chemical synthetic routes.

Synthesis, structural characterization, thermal analysis and antimicrobial assay of Co (II) complexes derived from benzaldehyde N4-substituted thiosemicarbazone

Microwave assisted Co (II) complexes of N4 -Substituted thiosemicarbazone were synthesized (TSC-La-f) and characterized by UV-visible spectra, IR spectra, 1H and 13C NMR spectra, elemental analysis, TGA, magnetic measurements and molar conductance. On the basis of spectral data, magnetic moment and thermal analysis square planar geometry assigned to Co(II) complexes. The electrolytic nature of the complexes was confirmed by their moderately high molar conductance values. All the metal complexes were screened for antimicrobial assay. Among all the complexes (TSC-Le) showed more activity than other Co (II) complexes. From this study it was concluded that complexes are more potent bactericide and fungicide than their corresponding ligands. Keywords: Thiosemicarbazones, benzaldehyde, Co(II) complexes, antimicrobial activity.

Synthesis and anticancer activity of Pd(II) and Pt(II) complexes of dodecyl based dithiocarbamate ligands: Insight into the C-H∙∙∙Pt interaction using X-ray structure, DFT, Hirshfeld surface and AIM analysis

Four new homoleptic complexes bis(N-dodecyl-N-benzyl)dithiocarbamato-S,S’)M(II) (where M=palladium (1), platinum (3)) and bis(N-dodecyl-N-(2-hydroxybenzyl)dithiocarbamato-S,S’)M(II) (where M=palladium (2), platinum (4)) were synthesized and characterized using elemental analysis, FTIR and NMR spectra. The crystal structures of 1 and 4 were solved by single crystal X-ray diffraction technique. Single crystal X-ray analysis of the two of the complexes (1 and 4) revealed the presence of a distorted square planar coordination geometry (S4) about the metal centre. Complex 4 revealed two intermolecular anagostic C-H∙∙∙Pt interactions which were characterized through a comprehensive set analysis using single crystal X-ray diffraction (experimental) and DFT, Hirshfeld surface analysis and AIM (theoretical) analysis. The electronic behavior, MEP surfaces, FMO and DOS studies of the complexes 1 and 4 were investigated employing DFT. A strong correlation has been found between both experimental and theoretical bond parameters. MTT assay was used to study the antitumor activities of 1–4 against MCF7 cancer cells. The results reveal that all complexes have fine anticancer activities.

Production and characterization of nano-magnetic material through different red mud reduction processes

Red mud (RM), is an industrial waste deriving from the production of primary aluminium, with about 200 Mtons generated annually. In this work, the reduction of RM for obtaining magnetic products with particular chemical-physical characteristics has been explored. RM reduction was carried out in a semi-closed reducing environment at a high processing temperature (750–1100 °C) in the presence of carbon-rich ash (CA) resulting from a commercial pyro-gasification plant and by using an H2 atmosphere. All the materials were characterized by elemental analysis, XRD diffraction technique, SEM/EDX microscopy, thermogravimetry and infrared spectroscopy. The materials obtained under the different conditions have in common the presence of small iron-magnetic domains (with different iron oxidation states), in the order of hundreds of nanometres, and by the ferro-magnetic or paramagnetic response to an external magnetic field. In particular, the material pre-treated with HCl (enriched in iron) and reduced with H2 showed very good magnetic responses, more iron in reduced oxidative states showing high ferro-magnetic responses to the external field. The synthesised materials are quite differents each others and appear to have several potential fields of application, as sorbents for specific wastewater pollutants, as materials for CO2 capture, for catalysis and (bio)sensing applications. Nevertheless, the high interconnection between the magnetic and non-magnetic phases limit the direct separation or the iron enrichment. Further efforts should be focused on the functional studies and subsequent LCA and LCC analyses.

Per aqueous liquid chromatography of Radix hedysari polysaccharides and Au nanoparticles co-functionalized stationary phase and its application in the determination of iridoids and phenylethanols

BackgroundHydrophilic Interaction Liquid Chromatography (HILIC) is an outstanding strategy for the challenging analysis of hydrophilic and polar components. Nevertheless, analysis under HILIC mode typically consumes 70%–95 % acetonitrile with the disadvantage of high analytical costs, being environmentally unfriendly and causing biohazards, which is not in line with the concept of green chromatography. Research has shown that Per Aqueous Liquid Chromatography (PALC) simultaneously emphasizes efficient analytical performance for hydrophilic analytes and green analytical concepts. The development of new PALC stationary phases with superior performance is necessary. ResultsIn this paper, silanized silica was sequentially subjected to esterification reaction, polymerization reaction and covalent bonding through five steps to obtain SiO2-RHP-AuNPs material, which was prepared as a novel stationary phase for PALC. Comprehensive characterization of the materials by means of Fourier transform infrared spectroscopy, Transmission scanning electron microscope, Elemental analysis and Thermogravimetric analysis showed the successful bonding of the functionalized groups on the original silica. The polymeric stationary phase based on Radix hedysari polysaccharide and Au nanoparticles had higher density of hydroxyl and ester functionalized groups. The Au nanoparticles upgraded their mesoporous structure and thermal stability, providing exceptional chromatographic performance and selectivity for chromatographic analysis. The influence of mobile phase water content, salt concentration, pH and column temperature on the retention behavior was evaluated. The novel Column was found to exhibit a dual mechanism of hydrophobic interactions/ion exchange interactions in a mobile phase with high water content. Significance and noveltyThe separation efficiency and selectivity of SiO2-RHP-AuNPs columns for synthetic pigments and organic acids in PALC mode were superior to those of commercial HILIC and C18 columns. In addition, a method for the determination of seven active ingredients in Fructus Ligustri Lucidi by SiO2-RHP-AuNPs column in PALC mode was developed. The method had good stability, reproducibility and accuracy, which was capable of realizing the quality evaluation of Chinese Materia Medicas.

Relative fuel property variation of gas-pressurized and conventional torrefaction for biochar performance assessment

Exploring biochar from gas-pressurized torrefaction for solid biofuel production is of great concern for the process performance assessment. This study conducts several relative indexes of biochars produced from gas-pressurized and conventional torrefaction, identifying the merits of the former. The results suggest that a higher pressure is more feasible for reducing biochar volume and enhancing energy efficiency. The results of the relative higher heating value (1.01–1.07) and relative enhancement factor (1.00–1.06) indicate that gas-pressurized torrefaction is more efficient for energy density improvement. Furthermore, gas-pressurized torrefaction dramatically facilitates biochar grindability, with the relative Hardgrove grindability index value ranging from 1.20 to 2.40. The proximate and elemental analysis results suggest that a higher pressure facilitates biochar carbonization and deoxygenation with a higher carbonized component. The energy consumption, efficiency, and expense calculation results imply that gas-pressurized torrefaction is more energy-efficient and cost-saving, with the relative upgrading energy index range of 1.00–1.12.

Trace Elements and Proximate Analysis of <i>Boswellia dalzielii</i> Stem Bark

Boswellia dalzielii (B. dalzielii) Hutch is a tree plant of the Burseraceae family found in Savannah woodlands. The decoction of stem bark has been reported to be useful in treating gastrointestinal diseases, rheumatism, septic sores, and sexual ailments. Additionally, it has demonstrated antifungal, antibacterial, and anti-inflammatory properties. The research was undertaken to evaluate the trace element contents and nutritional contents of the stem bark of B. dalzielii using standard methods of the Association of Official Analytical Chemists (AOAC). The elemental analysis showed the presence of: Zn (5.82±0.021 mg/kg), Cu (4.22±0.017 mg/kg), Mn (31.24±0.114 mg/kg), and Fe (9.12±0.318 mg/kg), Se (3.13m±0.223 g/kg) Cr (0.0026±0.211 mg/kg), Co (0.00 mg/kg), Mo (0.0016±0.001 mg/kg), Cd (0.0037±0.117 mg/kg), Ni (0.0016±0.324 mg/kg), and I (4.15±0.214 mg/kg). While the proximate analysis revealed the presence of the following: ash content (5.97±0.315%), moisture (6.22±0.115%), protein (18.52±0.018%), fiber 16.2±0.215%), crude fat (6.02±0.002%), and carbohydrate (31.73±0.224%). Trace elements have well-characterized physiological functions within the body. They regulate biological processes, thereby stabilizing the structures of cells when they are supplied at the normal level, but their deficiency leads to different kinds of diseases. The study suggests that the trace elements present in the bark sample of B. dalzielii may be of value and may have prognostic significance in the early diagnosis and therapy evaluation of some diseases, especially various types of cancer, as well as in anti-diabetic agents. The results of the proximate analysis depict the potentiality of the plant as a good source of nutraceuticals.