Characterization Of Different Fractions Research Articles

Electric arc pyrolysis of different fractions derived from waste tire pyrolysis oil

The paper reports the experimental results on extraction and characterization of different fractions (light (<180 °C), middle (180–350 °C), and heavy (>350 °C)) derived from pyrolysis oil of waste tires of mining vehicles, followed by their electric arc pyrolysis in order to produce nanosized carbon material. The released gas was found to contain 20.4–37.1 vol% hydrogen, 7.4–24.9 vol% methane, and 24.7–27.9 vol% carbon monoxide. The carbon material obtained was presented by an array of nanosized particles (30–250 nm) with a graphite-like structure and a wide range of specific surface area values (Ssf = 38.8–79.7 m2/g). The content of carbon and sulfur was 98.3–99.1 wt% and 0.1–0.3 wt%, respectively. Transmission electron microscopic analysis of the test samples revealed two types of carbon nanostructures of different morphology: polyhedral graphite and carbon nano-onions. Characteristics of the samples obtained from pyrolysis oil and its fraction with a boiling point exceeding 350 °C were the closest to those of carbon black.

Evaluation of Biological Activity and Pharmacological Attributes of Pariploca aphylla: Potential Source of Functional Food and Nutraceuticals

Functional foods and nutraceuticals are gaining popularity as they are being developed and commercialized with the aim of reducing the risk of various diseases and their treatment. In this study, antiradical activity guided fractionation of Pariploca aphylla (P. aphylla) crude extract was conducted. A crude methanolic extract of P. aphylla was prepared and then fractionated using different solvents, including hexane, chloroform, ethyl acetate, butanol, and water. This approach allowed for the isolation and characterization of different fractions of P. aphylla with potential antioxidant activity. These fractions were tested for the determination of total phenolic content, antiradical (DPPH• and ABTS•+) potential and HPLC quantification of phenolic acids. Among all the tested fractions, butanol fraction exhibited highest phenolic content and significant antiradical potential. Butanol faction was further sub-fractionated using a silica gel-loaded column and 18 sub-fractions were obtained. Antiradical potential of all 18 sub-fractions was determined and sub-fraction 12 was found having highest radical scavenging potential. Structures of compounds in sub-fraction 12 were identified and quantified using GC-MS. Among all the identified compounds, 7-Trimethylsilyloxytridecane (C16H36OSi) and 1,2-bis(trimethylsiloxy)ethane (C8H22O2Si2) were found in highest ratio. All of the compounds can be declared having high anti-radical potential that can be extracted or synthesized for possible exploitation as functional food or nutraceuticals.

Metabolites Profiling and In Vitro Biological Characterization of Different Fractions of Cliona sp. Marine Sponge from the Red Sea Egypt.

Red Sea marine sponges are an important source of biologically active natural products. Therefore, the present study aimed to investigate, for the first time, the components of n-hexane, dichloromethane, and ethyl acetate fractions of Cliona sp. marine sponge collected from the Red Sea, Egypt using UPLC-ESI-MS/MS (Ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry) analysis. The analysis revealed the tentative identification of 23, 16, and 24 compounds from the n-hexane, dichloromethane, and ethyl acetate fractions of Cliona sp., respectively. In addition, the examination of these fractions resulted in the isolation and identification of three sterols and one amino acid. The identification of the isolated compounds was confirmed by 1D and 2D NMR (Nuclear Magnetic Resonance), and MS (Mass spectrometry), and IR (Infrared) spectroscopy. The in vitro cytotoxic, antioxidant, and antimicrobial activities of the total ethanolic extract and its sub-fractions were also evaluated. Interestingly, the ethyl acetate fraction showed potent cytotoxic activity against colon (HCT-116) and human larynx carcinoma (HEP-2) cell lines with IC50 (Half-maximal Inhibitory Concentration) 6.11 ± 0.2 and 12.6 ± 0.9 µg/mL, respectively. However, the dichloromethane fraction showed strong antioxidant activity, with IC50 75.53 ± 3.41 µg/mL. Notably, the total ethanolic extract showed the strongest antibacterial activity against Staphylococcus aureus and Escherichia coli, with MIC (Minimum Inhibitory Concentration) 62.5 ± 0.82 and 125 ± 0.62 µg/mL, respectively, compared to other fractions. In conclusion, this is the first report on the secondary metabolites content and biological activities of Cliona sp. from the Red Sea, Egypt. It also highlights the need for further research on the most active fractions against various cancer cell lines and resistant bacterial and fungal strains. Cliona sp. extract and its fractions could be a potential source of novel and safe natural drugs with a wide range of medicinal and pharmaceutical applications.

The bio- and thermal lability of dissolved organic matter as revealed by high-resolution mass spectrometry and thermal chemical analyses

It is critical to understand the chemical structures and lability of dissolved organic matter (DOM) in aquatic environments, as DOM represents one of the largest reduced carbon pools on earth. To achieve a comprehensive view of its composition and reactivity, DOM from both riverine and coastal waters were concurrently extracted via both ultrafiltration and modified styrene divinyl benzene polymer (PPL) based solid-phase-extraction (SPE), and further compared through multi-dimensional angles, including elemental analysis, total hydrolyzable amino acid composition, high-resolution liquid chromatography mass spectrometry (under both electrospray ionization modes), and thermochemical analysis. With a very low percentage (< 5%) of shared molecules, ultrafiltered-DOM (UDOM) and SPE-extracted DOM (SPEDOM) showed distinct differences in their bio- and thermal labilities. SPEDOM not only contained more “degraded” biomarkers, such as glycine, β-alanine, and γ-aminobutyric acid, but was also dominated by a higher abundance of more bio-recalcitrant lignin-like structures. Furthermore, thermogravimetric analysis revealed a higher activation energy of SPEDOM (138.8 ± 0.5 kJ·mol−1) than that of UDOM (125.4 ± 2.8 kJ·mol−1), suggesting that SPEDOM is more thermally recalcitrant than UDOM. Consistently, thermal slicing ramped pyrolysis showed a lower percentage of recalcitrant pyrolyzates (e.g., aromatic and phenol structures), but a higher contribution of labile compound classes (e.g., aliphatic structures) in UDOM, as well as a higher diversity of pyrolyzates from UDOM than SPEDOM. Taken together, our results demonstrated a highly heterogeneous nature in DOM composition and distinctly different bio- and thermal labilities between UDOM and SPEDOM, indicating that characterization of different fractions of DOM is needed for a comprehensive evaluation of natural DOM.

A Comprehensive Characterization of Different Fractions of Corn Stover and Their Relationships to Multipollutant Sorption Characteristics

Corn stover (CS) is mainly composed of three parts: pith (CSP), rind (CSR), and leaf (CSL). These parts have different lignocellulosic constituents and structural properties. Herein, biosorbents derived from individual corn stover constituents were prepared in an effort to determine the significance of each constituent for multipollutant removal. In this study, SEM, BET, XRD, FTIR, XPS, fibre composition, and contact angle measurements were used to characterize and analyse the physical and chemical properties of the three components of CS and to study their adsorption effects, adsorption isotherms, and kinetics. The lignocellulosic compositions of CSP and CSR were similar, the cellulose content in CSP and CSR was significantly higher than that in CSL, and the hemicellulose content of CSL was much higher than those of CSP and CSR. The minimum lignin content was found in CSP, and the maximum lignin content was found in CSR. The results show that each component had a certain adsorption effect on typical organic pollutants (antibiotics, oils, and dyes). CSP had the strongest oil adsorption capacity, CSR was more suitable for adsorbing antibiotics, and CSL had outstanding adsorption capacity for dye. The pseudo-second-order model and the Langmuir adsorption isotherm model could describe the adsorption processes well, and they consisted of monolayer adsorption accompanied by chemical adsorption reactions. The focus of this study was to provide references for selecting effective adsorbent precursors to remove organic pollutants from wastewater.

Raman spectroscopy for the characterization of different fractions of hemp essential oil extracted at 130 °C using steam distillation method

In this study, Raman spectroscopy along with Principal Component Analysis (PCA) is used for the characterization of pure essential oil (pure EO) isolated from the leaves of the Hemp (Cannabis sativa L.,) as well as its different fractions obtained by fractional distillation process. Raman spectra of pure Hemp essential oil and its different fractions show characteristic key bands of main volatile terpenes and terpenoids, which significantly differentiate them from each other. These bands provide information about the chemical composition of sample under investigation and hence can be used as Raman spectral markers for the qualitative monitoring of the pure EO and different fractions containing different active compounds. PCA differentiates the Raman spectral data into different clusters and loadings of the PCA further confirm the biological origin of the different fractions of the essential oil.

Pharmacological characterization of different fractions of Calotropis procera (Asclepiadaceae) in streptozotocin induced experimental model of diabetic neuropathy

Ethnopharmacological relevanceCalotropis procera (Ait.) R.Br. is one of an ancient traditional shrub, which has been used for the treatment of diabetes, pain and inflammation for thousands of years in India. The root extract of Calotropis procera has been widely used by the tribal׳s of district Udaipur, Rajasthan (India) for treatment of diabetes mellitus and its associated complications like diabetic neuropathy. The present study was performed to explore the protective effect of root, stem and leaf extracts of Calotropis procera in diabetes and diabetic neuropathy against tactile allodynia, mechanical hyperalgesia and thermal hyperalgesia in streptozotocin induced diabetic rats. Materials and methodsDiabetes and peripheral neuropathy were induced in Wistar rats by injection of streptozotocin (45mg/kg/intraperitoneally). The roots, stem and leaves of Calotropis procera were sequentially extracted with petroleum ether, chloroform, ethyl acetate and methanol. All the extracts were assessed by oral administration at 100 and 250mg/kg in streptozotocin diabetic rats. The following compounds were used as positive controls: insulin NPH (1IU/kg/day), metformin (500mg/kg/day), glibenclamide (2.5mg/kg/day) and a combination of acarbose (20mg/kg/day) with methylcobalamine (500µg/kg/day). In contrast, the streptozotocin induced untreated diabetic rats termed as negative control. Thermal hyperalgesia, mechanical hyperalgesia and tactile allodynia were evaluated in all groups of streptozotocin diabetic rats to assess the extent of neuropathy by Eddy׳s hot plate, tail immersion, Randall–Selitto and Von Frey hair tests. The basal nociceptive thresholds were assessed in week 4 of post streptozotocin injection. All groups received their treatment on a regular basis from 28 to 42 days following a confirmation of diabetic neuropathy. The nociceptive thresholds were assessed in all groups in week 5 and 6. The histopathology of pancreas and biochemical estimations of plasma insulin and glycosylated haemoglobin (HbA1C%) levels were also performed in week 6 of post streptozotocin injection. ResultsThe negative control rats developed diabetes and diabetic neuropathy after 6 week of streptozotocin administration distinguished by significant (p<0.01) hyperalgesia and tactile allodynia with enhanced HbA1C% level compared to normoglycemic rats. Chronic administration of root methanol, stem methanol and leaf ethyl-acetate extracts of Calotropis procera for 2 weeks at 100 and 250mg/kg doses significantly (p<0.01) attenuated the diabetes induced mechanical hyperalgesia, thermal hyperalgesia, tactile allodynia and HbA1C% level in streptozotocin diabetic rats as compared to negative control rats. Further, the root methanol extract of Calotropis procera in 100mg/kg dose showed the regeneration capability of β cells in the histology of pancreas with significant (p<0.01) improvement in plasma insulin level in streptozotocin diabetic rats compared to negative control rats. ConclusionRoot methanol extract of Calotropis procera (100mg/kg) has shown ameliorative effect in diabetic neuropathy which may be attributed by its multiple actions including potent hypoglycemic and antioxidant.

Depolymerization of nylon 6 waste fibers

AbstractThe depolymerization of nylon 6 was carried out with various solvents, such as formic acid, hydrochloric acid, and sulfuric acid, followed by heating under reflux for different times. From the polymer dissolved and refluxed in formic acid, degradation products with different ranges of molecular weights were collected by fractional precipitation, with small lots of distilled water added as a nonsolvent. The characterization of different fractions was carried out by the measurement of the viscosity‐average molecular weight, the number‐average molecular weight, and the number of amino end groups. The presence of the monomer, aminocaproic acid, was confirmed by thin‐layer chromatography in the case of hydrochloric acid treated nylon 6. With a strongly acidic ion‐exchange resin, the monomer was separated in its purest form, and the melting point was noted. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 186–190, 2006

A brief overview of modern directions in marine DOC studies Part IIFor Part I see ref. 52.—Recent progress in marine DOC studies

Progress made in analytical techniques allows the formulation of new concepts in the biogeochemistry of organic carbon. The second part of our review summarizes the latest evolution and introduces new ideas in the biogeochemistry of marine dissolved organic carbon (DOC). Via classification of different fractions and sources of DOC, characterization of its composition, age and availability for bacterial utilization, and fate of DOC, we show the role of DOC in the global carbon cycle and the significance of bulk DOC in the oceans. Special emphasis is placed on the microbial loop in the cycling of DOC and its relation with higher trophic levels (phytoplankton and zooplankton). Significant progress has also been made in the study of the roles of colloidal organic material in metal complexation, ultraviolet radiation in dissolved organic matter photochemical oxidation, and chromophore-containing constituents of DOC as the signature of DOC for satellite observations. The importance of bulk DOC in the global carbon cycle requires the inclusion of this fraction in the regional and global carbon models. We predict that future DOC study in the ocean will focus on the development of sophisticated, almost continuously recording, moored DOC instrument arrays for the monitoring of small-scale DOC horizontal and vertical patchiness; widespread time series stations including estuarine, coastal and open environments; more detailed chemical characterization of different fractions of organic carbon from diverse marine habitats; parameterization of predictive models of DOC cycling on regional and global scales, incorporating the microbial loop; and finally, monitoring of DOC dynamics from satellites on regional and global scales.

Size and shape of isolated rat liver mitochondria.

The dimensions of unfixed rat liver mitochondria, isolated in 0.44 M sucrose, were measured on photomicrographs taken by phase-contrast microscopy. The lengths ranged from the limit of resolution of the microscope (ca. 0.2 μ) to ca. 5 μ. The smallest measured particle had a calculated volume of 0.008 μ3 and the largest 3.85 μ3. Separate fractions of mitochondria, in order of decreasing sedimentation rate and fragility (Can. J. Biochem. 44, 497), were found to range in mean size from 0.92 μ long × 0.59 μ in diameter (fraction I), through 0.84 μ × 0.59 μ (fraction III) to 0.60 μ × 0.48 μ (fraction V). The limitations and errors in the measurements have been discussed. While these measurements cannot be considered "correct" in an absolute sense, they more closely represent the actual size of unfixed isolated mitochondria than do previously reported measurements, and reliably allow size characterization of different fractions.