Publications by authors named "Ayman Ghfar"

29 Publications

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Enhanced solar light photocatalytic performance of Fe-ZnO in the presence of HO, SO, and HSO for degradation of chlorpyrifos from agricultural wastes: Toxicities investigation.

Chemosphere 2021 Sep 22;287(Pt 4):132331. Epub 2021 Sep 22.

Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus Raiwind Road, Lahore, 54000, Pakistan.

This study reported Fe doped zinc oxide (Fe-ZnO) synthesis to degrade chlorpyrifos (CPY), a highly toxic organophosphate pesticide and important sources of agricultural wastes. Fourier transform infrared, X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectroscopic analyses showed successful formation of the Fe-ZnO with highly crystalline and amorphous nature. Water collected from agricultural wastes were treated with Fe-ZnO and the results showed 67% degradation of CPY by Fe-ZnO versus 39% by ZnO at 140 min treatment time. Detail mechanism involving reactive oxygen species production from solar light activated Fe-ZnO and their role in degradation of CPY was assessed. Use of HO, peroxydisulfate (SO) and peroxymonosulfate (HSO) with Fe-ZnO under solar irradiation promoted removal of CPY. The peroxides yielded hydroxyl (OH) and sulfate radical () under solar irradiation mediated by Fe-ZnO. Effects of several parameters including concentration of pollutant and oxidants, pH, co-existing ions, and presence of natural organic matter on CPY degradation were studied. Among peroxides, HSO revealed to provide better performance. The prepared Fe-ZnO showed high reusability and greater mineralization of CPY. The GC-MS analysis showed degradation of CPY resulted into several transformation products (TPs). Toxicity analysis of CPY as well as its TPs was performed and the formation of non-toxic acetate imply greater capability of the treatment technology.
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http://dx.doi.org/10.1016/j.chemosphere.2021.132331DOI Listing
September 2021

Biological approach in deinking of waste paper using bacterial cellulase as an effective enzyme catalyst.

Chemosphere 2021 Sep 2;287(Pt 2):132088. Epub 2021 Sep 2.

Department of Bionanotechnology, Gachon University, 13120, South Korea.

Paper has become the basic elixir in everyone's activities and usage of paper has increased day by day, the waste generated by paper is also enormous. The primary source of paper is wood (tree) yet, waste paper is environmentally good and biodegradable; however, it is the primary source of deforestation. Current research aims to find an alternate way to recycle paper in the biological approach. Hence in our work, twelve cellulose-producing bacteria were isolated, out of which one bacterial strain proved to be the best. Cellulase enzyme was extracted and purified, and used for enzymatic de-inking of photocopy papers. The optimal conditions for cellulase synthesis were at 60 °C, glucose as the only carbon source, and potassium nitrate as the nitrogen source. The enzyme demonstrated excellent de-inking at a lower pulp consistency of 3% with a 20% enzyme dose. The cellulose and hemicellulose levels decreased, which can be attributed to fiber breaking. Further, the changes in the functional groups identified by Fourier-transform infrared spectroscopy analysis and the changes in the surface morphology of the pulp fibers were obtained using scanning electron microscope analysis.
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http://dx.doi.org/10.1016/j.chemosphere.2021.132088DOI Listing
September 2021

Salinity mitigates cadmium-induced phytotoxicity in quinoa (Chenopodium quinoa Willd.) by limiting the Cd uptake and improved responses to oxidative stress: implications for phytoremediation.

Environ Geochem Health 2021 Sep 2. Epub 2021 Sep 2.

Centre for Environmental and Climate Science, Lund University, 22362, Lund, Sweden.

Cadmium (Cd) contamination and soil salinity are the main environmental issues reducing crop productivity. This study aimed to examine the combined effects of salinity (NaCl) and Cd on the physiological and biochemical attributes of quinoa (Chenopodium quinoa Willd.). For this purpose, 30-day-old plants of quinoa genotype "Puno" were transplanted in Hoagland's nutrient solution containing diverse concentrations of Cd: 0, 50, 100, 200 µM Cd, and salinity: 0, 150, and 300 mM NaCl. Results demonstrated that plant growth, stomatal conductance, and pigment contents were significantly lower at all Cd concentrations than the control plants. Quinoa plants exhibited improved growth and tolerance against Cd when grown at a lower level of salinity (150 mM NaCl) combined with Cd. In contrast, the elevated concentration of salinity (300 mM NaCl) combined with Cd reduced shoot and root growth of experimental plants more than 50%. Combined application of salinity and Cd increased Na (25-fold), while lessened the Cd (twofold) and K (1.5-fold) uptake. A blend of high concentrations of Na and Cd caused overproduction of HO (eightfold higher than control) contents and triggered lipid peroxidation. The activities of antioxidant enzymes: ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) were 13, 12, 7 and ninefold higher than control to mitigate the oxidative stress. Due to restricted root to shoot translocation, and greater tolerance potential against Cd, the quinoa genotype, Puno, is suitable for phytostabilization of Cd in saline soils.
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http://dx.doi.org/10.1007/s10653-021-01082-yDOI Listing
September 2021

Application of a novel nanocomposite containing micro-nutrient solubilizing bacterial strains and CeO nanocomposite as bio-fertilizer.

Chemosphere 2021 Aug 9;286(Pt 3):131800. Epub 2021 Aug 9.

Department of Bionanotechnology, Gachon University, 13120, South Korea.

Chemical fertilizers are used in modern agricultural practice to increase plant output. They possess anthropogenic compounds which are hazardous, result in poor soil quality, poor crop nutrition and pollutes the water table. Currently, food crops that lack in micro-nutrients (Zn, silicates and Se) can be enriched with micronutrients by use of fertilizers. Eco-friendly bio-fertilizers have been proved to provide a known population of microorganisms that create a mutual benefit to the plants & the rhizosphere soil. Nanomaterials are often used in plant fertilizer formulation, allowing for controlled release and targeted delivery of beneficial nanoscale components, as well as to boost plant production and reduce environmental pollutants. In the present study we identified a multipotent micronutrient solubilizing bacterium (MSB) - Pseudomonas gessardi and Pseudomonas azotoformans as a bio-fertiliser. Comparative study of the formulated MSB, with nanocomposite prepared with the soya chunks as natural carrier material and chemically synthesized cerium oxide was performed on the growth of fenugreek for its effectiveness. The SEM images of nanocomposite showed the non-uniform distribution of CeO in bio-inoculant with an average size of 25.24 nm. The current study deals with increase in the shoot and root length of the fenugreek plant with only 75 ppm of CeO in nanocomposite, thereby preventing bioaccumulation of Ce in soil. This work gives a potential use of CeO2 nanocomposite with MSB bio-inoculants which could be applied to soil deficient with the micronutrients that can enhance the crop yield.
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http://dx.doi.org/10.1016/j.chemosphere.2021.131800DOI Listing
August 2021

Investigation of mechanism of heavy metals (Cr, Pb& Zn) adsorption from aqueous medium using rice husk ash: Kinetic and thermodynamic approach.

Chemosphere 2021 Aug 6;286(Pt 3):131796. Epub 2021 Aug 6.

Division of Electronics and Electrical Engineering, Dongguk University-Seoul, Seoul, 04620, Republic of Korea.

In this work, we examined the possibility on the application of rice husk as biosorbent for the elimination of heavy metal ions (chromium, lead, and zinc) existing in the aqueous solutions. The biosorbent was prepared from rice husk powder and modified with 0.1 N of HCl for creating the functional groups and increase specific surface area. The FT-IR spectra, SEM& EDX studies of rice hulls powder were examined for the pristine adsorbent and after the adsorption of heavy metal ions. The batch adsorption technique was adopted for this work and adsorption parameters were optimized. The maximum efficiency of adsorption is obtained at 6.0 pH, 1 h of contact duration, the rice husk dosage is 2.5 g/L, and temperature of 30°C for 25 mg/L of Cr, Pb & Zn metal ion solutions. The Cr, Pb & Zn metal ions are removed up to 87.12 %, 88.63 % & 99.28 %, respectively, using the rice husk powder. The adsorption process follows the Temkin & D-R isotherm model. Elovich model was fitted against the kinetic data of metal ion adsorption. Based on the experimental observations, the rice husk powder can be considered as a low cost adsorbent for heavy metal ion removal from the industrial effluent.
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http://dx.doi.org/10.1016/j.chemosphere.2021.131796DOI Listing
August 2021

Production of Terretonin N and Butyrolactone I by Thermophilic TM8 Promoted Apoptosis and Cell Death in Human Prostate and Ovarian Cancer Cells.

Molecules 2021 May 10;26(9). Epub 2021 May 10.

Department of Pharmaceutical Practice, College of Pharmacy, Princess Nourah bint Abdulrahman University, Riyadh 11451, Saudi Arabia.

The anticancer activity of terretonin N () and butyrolactone I (), obtained from the thermophilic fungus TM8, was intensively studied against prostate adenocarcinoma (PC-3) and ovary adenocarcinoma (SKOV3) human cell lines. According to this study, both compounds showed potent cytotoxicity towards ovarian adenocarcinoma cells (SKOV3) with IC 1.2 and 0.6 μg/mL, respectively. With respect to metastatic prostate cells (PC-3), the two compounds and showed a significantly promising cytotoxicity effect with IC of 7.4 and 4.5 μg/mL, respectively. The tested fungal metabolites showed higher rates of early and late apoptosis with little or no necrotic apoptotic pathway in all treated prostate adenocarcinoma (PC-3) and ovary adenocarcinoma (SKOV3) human cell lines, respectively. The results reported in this study confirmed the promising biological properties of terretonin N (1) and butyrolactone I (2) as anticancer agents via the induction of cellular apoptosis. However, further studies are needed to elucidate the molecular mechanism by which cellular apoptosis is induced in cancer cells.
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http://dx.doi.org/10.3390/molecules26092816DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8126039PMC
May 2021

A comparison of chiral resolution of antifungal agents on different polysaccharide chiral columns under various mobile phase modes: Application in the biological samples.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Jun 30;1175:122738. Epub 2021 Apr 30.

Department of Pharmaceutical Practice, College of Pharmacy, Princess Nourah bint Abdulrahman University, Riyadh 11671, Saudi Arabia.

The current article describes the chiral separation of tioconazole, miconazole, isoconazole, sertaconazole and terconazole, with Lux i-Cellulose 5 and Lux i-Amylose-1 chiral columns under organic polar, normal and reversed mobile phases modes. The mobile phase flow rate was 1 mL/min with 230 nm detection at 25 ± 1 °C temperature. The polar organic mobile phases offered certain advantages for separation such as short analysis time, order of elution, high plate numbers and favorable signal to noise ratio. The values of k, α and Rs were ranged from 0.6 to 7.87, 1.10 to 1.62 and 0.37 to 5.72 in polar organic, 0.15 to 43.86, 1.02 to 2.01 and 0.36 to 8.03 in normal, and 0.34 to 15.99, 1.03 to 1.40 and 0.59 to 4.18 in reversed phases modes, respectively. The reported methods were applied in urine samples and the results were satisfactory. The reported methods were applied to the analysis of urine samples.
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http://dx.doi.org/10.1016/j.jchromb.2021.122738DOI Listing
June 2021

Investigation the Effects of Green-Synthesized Copper Nanoparticles on the Performance of Activated Carbon-Chitosan-Alginate for the Removal of Cr(VI) from Aqueous Solution.

Molecules 2021 Apr 29;26(9). Epub 2021 Apr 29.

Advanced Materials Research Chair, Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.

In the present investigation, green nano-zerovalent copper (GnZVCu), activated carbon (AC), chitosan (CS) and alginate (ALG) nanocomposites were produced and used for the elimination of chromium (VI) from a polluted solution. The nanocomposites GnZVCu/AC-CS-alginate and AC-CS-alginate were prepared. Analysis and characterization were performed by the following techniques: X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The SEM analysis revealed that the nanocomposites are extremely mesoporous, which leads to the greatest adsorption of Cr (i.e., 97.5% and 95%) for GnZVCu/AC-CS-alginate and AC-CS-alginate, respectively. The adsorption efficiency was enhanced by coupling GnZVCu with AC-CS-alginate with a contact time of 40 min. The maximum elimination of Cr with the two nanocomposites was achieved at pH 2. The isotherm model, Freundlich adsorption isotherm and kinetics model and P.S.O.R kinetic models were discovered to be better suited to describe the exclusion of Cr by the nanocomposites. The results suggested that the synthesized nanocomposites are promising for the segregation of Cr from polluted solutions, specially the GnZVCu/AC-CS-alginate nanocomposite.
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http://dx.doi.org/10.3390/molecules26092617DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8125594PMC
April 2021

Visible light driven reduced graphene oxide supported ZnMgAl LTH/ZnO/g-CN nanohybrid photocatalyst with notable two-dimension formation for enhanced photocatalytic activity towards organic dye degradation.

Environ Res 2021 06 26;197:111079. Epub 2021 Mar 26.

Chemistry Department P. O. Box 84428, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, 11671, Saudi Arabia.

In this study, 2D/2D/2D heterostructured r-GO/LTH/ZnO/g-CN nanohybrid were synthesized through hydrothermal method. The strong electrostatic interaction between the negatively charged g-CN and r-GO nanosheets with positively charged layered triple hydroxide (LTH) nanosheets are effectively influences the successful formation of heterojunction. The LTH nanosheets are well spread on the g-CN nanosheets combined with r-GO. In particular, the as prepared heterojunction shows a better photocatalytic degradation activity compared to pristine samples and the significant enhancement in the photocatalytic performance is mainly accredited to the large interfacial charge transition of photogenerated charge carriers under the visible light irradiation. Although the 2D/2D/2D heterojunction effectively hinders the charge carrier recombination resulting high photocatalytic activity with good stability. In addition, the r-GO supported LTH/ZnO/g-CN heterojunction shows high photo-stability after sequential experimental runs with no obvious change in the dye degradation process. Consequently, the role of active species was investigated over the r-GO/LTH/ZnO/g-CN heterojunction with the help of different scavengers.
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http://dx.doi.org/10.1016/j.envres.2021.111079DOI Listing
June 2021

Preparation of value-added metal-organic frameworks for high-performance liquid chromatography. Towards green chromatographic columns.

J Chromatogr A 2021 Feb 29;1638:461857. Epub 2020 Dec 29.

Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.

This work applies the concepts of green chemistry, where polyethylene terephthalate (PET) bottles were used as the acid-dicarboxylic linker source for the synthesis of MIL-53(Al) metal organic frameworks (MOFs) and then used as a stationary phase for the separation of various solutes and compared with MIL-53(Al) synthesized from traditional terephthalic acid. Both synthesized MIL-53(Al) MOFs were characterized by scanning electron microscopy (SEM), FT-IR, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and specific surface area analysis. Eight groups of standard analytes in addition to real samples were tested to evaluate the separation performance of the MIL-53(Al) packed columns in HPLC under various chromatographic conditions. Based on elution order of the studied compounds and the effects of mobile phase composition, the working mechanism was reversed phase mode in the presence of size-exclusion effects for large molecules, which exceeded the dynamic diameter of MIL-53(Al) (~7.6 Å). The effects of stationary phase sieving, mobile phase flow rate and composition, injected sample mass, and temperature were investigated relative to the chromatographic behavior of MIL-53(Al). MIL-53(Al) particle sieving before packing reduced peak broadening and significantly enhanced the chromatographic performance of the prepared columns up to 2.26 times relative to the number of theoretical plates. The MIL-53(Al) packed columns offered high-resolution separation for all studied mixtures with R >2 and good stability and long-term durability. At optimal conditions, the prepared columns exhibited efficiencies between 5600-63200 plates m. Higher efficiencies were observed for alkylbenzenes and polyaromatic hydrocarbons as the organic linker in the MIL-53(Al) structure, which improved retention and separation of aromatics through π-π interactions. Thermodynamic parameters including ΔH, ΔS, and ΔG for the transfer of analyte from the mobile phase to the MIL-53(Al) stationary phase were studied. Compared with previously cited MOFs packed columns, the present MIL-53(Al) columns gave comparable selectivity and much better efficiency for most of the studied chemicals at optimum conditions, indicating the feasibility of MIL-53(Al) as a stationary phase for HPLC applications.
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http://dx.doi.org/10.1016/j.chroma.2020.461857DOI Listing
February 2021

Nano-clay as a solid phase microextractor of copper, cadmium and lead for ultra-trace quantification by ICP-MS.

Anal Methods 2020 11 7;12(41):4949-4955. Epub 2020 Oct 7.

Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Kingdom of Saudi Arabia.

Heavy metal microextraction and determination in daily used water is accurately achieved by applying nano-clay as an extractor. The conditions for adsorption/elution of Cu(ii), Cd(ii) and Pb(ii) were investigated by adjusting the pH of samples, sample volume and the type of eluent. The nano-clay showed superior efficiency for microextraction of Cu(ii), Cd(ii) and Pb(ii) at pH 2 using 2 mL of nitric acid (1 M) as the eluent. The microextraction procedure showed high recovery% by changing the sample volume from 15 mL to 70 mL. The preconcentration factor was found to be 37.5. The LOD and LOQ were 1.8, 1.3, and 1.9 μg L and 5.3, 3.9, and 5.7 μg L for Cu(ii), Cd(ii) and Pb(ii) respectively. The addition/recovery from different water samples showed recovery% in the range 88-105 which confirms the efficiency and the accuracy of the developed solid phase microextraction using nano-clay for enrichment of Cu(ii), Cd(ii) and Pb(ii).
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http://dx.doi.org/10.1039/d0ay01343aDOI Listing
November 2020

Metal organic frameworks enhanced dispersive solid phase microextraction of malathion before detection by UHPLC-MS/MS.

J Sep Sci 2020 Aug 6;43(15):3103-3109. Epub 2020 Jul 6.

Science Faculty, Department of Chemistry, Erciyes University, Kayseri, Turkey.

Metal organic frameworks are considered as an efficient and promised adsorbent for separation of several ions and compounds from solutions due to its unique geometric structure. Herein, copper-benzyl tricarboxylic acid based metal organic frameworks have showed a high efficiency in enrichment and microextraction of malathion from food and water samples. The microextraction procedures were followed by determination of malathion by ultra high performance liquid chromatography with tandem mass spectrometry. The optimum recoveries for malathion were obtained at pH 6, and with using 2 mL of ethyl acetate as the eluent. The microextraction procedures showed a detection limits and the quantification limits of 4.0 and 10.0 µg/L, respectively. The intra- and interday precision showed a relative standard deviation% less than 10. The feasibility of the proposed procedure was determined by evaluating the addition/recovery studies of malathion from the real samples. The absolute recovery% was ≥92%. Furthermore, some ions were tested as cointerfering ions, and the recovery% was 93-100%. These results confirm that the developed microextraction procedure based on copper-benzyl tricarboxylic acid based metal organic frameworks as extractor for dispersive solid phase microextraction is matrix-independent, and can be applied for various real samples including different matrix or various malathion content.
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http://dx.doi.org/10.1002/jssc.202000033DOI Listing
August 2020

Bioremediation of Explosive TNT by .

Molecules 2020 Mar 19;25(6). Epub 2020 Mar 19.

Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia, P.O. Box 2455, Riyadh 11451, Saudi Arabia.

Nitroaromatic and nitroamine compounds such as 2,4,6-trinitrotoluene (TNT) are teratogenic, cytotoxic, and may cause cellular mutations in humans, animals, plants, and microorganisms. Microbial-based bioremediation technologies have been shown to offer several advantages against the cellular toxicity of nitro-organic compounds. Thus, the current study was designed to evaluate the ability of to degrade nitrogenous explosives, such as TNT, by microbiological assay and Gas chromatography-mass spectrometry (GC-MS) analysis. In this study, fungus was shown to have the ability to decompose, and TNT explosives were used at doses of 50 and 100 ppm on the respective growth media as a nitrogenous source needed for normal growth. The GC/MS analysis confirmed the biodegradable efficiency of TNT, whereas the initial retention peak of the TNT compounds disappeared, and another two peaks appeared at the retention times of 9.31 and 13.14 min. Mass spectrum analysis identified 5-(hydroxymethyl)-2-furancarboxaldehyde with the molecular formula CHO and a molecular weight of 126 g·mol as the major compound, and 4-propyl benzaldehyde with a formula of CHO and a molecular weight of 148 g mol as the minor compound, both resulting from the biodegradation of TNT by . In conclusion, could be used in microbial-based bioremediation technologies as a biological agent to eradicate the toxicity of the TNT explosive. In addition, future molecular-based studies should be conducted to clearly identify the enzymes and the corresponding genes that give the ability to degrade and remediate TNT explosives. This could help in the eradication of soils contaminated with explosives or other toxic biohazards.
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http://dx.doi.org/10.3390/molecules25061393DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7144562PMC
March 2020

Phosphonium-based Ionic Liquid Modified Activated Carbon from Mixed Recyclable Waste for Mercury(II) Uptake.

Molecules 2019 Feb 5;24(3). Epub 2019 Feb 5.

Advanced Materials Research Chair, Chemistry Department P. O. Box 2455, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.

The contamination of water surfaces by mercury is a dangerous environmental problem due to its toxicity, which leads kidney damage. Activated carbon from mixed recyclable waste modified by phosphonium-based ionic liquid (IL-ACMRW) was therefore prepared and evaluated for Hg(II) remediation. The activated carbon used in this study was prepared from mixed waste, including cardboard, papers and palm wastes as cheap raw materials. The mixed Recyclable Waste Activated Carbon was combined with trihexyl(tetradecyl)phosphonium Bis2,4,4-(trimethylpentyl)phosphinate (Cyphos IL 104) ionic liquid to form an adsorbent with organic-inorganic content, in order to improve the Hg(II) uptake from aqueous solutions. FTIR confirms the presence of P, C=O and OH after this modification. The adsorption process was investigated and the evaluated results showed that the capacity was 124 mg/g at pH 4, with a contact time of 90 min, an adsorbent dose of 0.4 g/L, and a Hg(II) concentration of 50 mg/L. This Hg(II) adsorption capacity is superior than that reported in the literature for modified multiwall carbon nanotubes. The adsorption of Hg(II) on the modified activated carbon from mixed recyclable waste was found to follow the pseudo second-order kinetics model. Isotherms of adsorption were analyzed via Freundlich and Langmuir models. The results indicated that Freundlich is the best model to describe the process, suggesting multilayer adsorption.
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http://dx.doi.org/10.3390/molecules24030570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384760PMC
February 2019

Visible photodegradation of ibuprofen and 2,4-D in simulated waste water using sustainable metal free-hybrids based on carbon nitride and biochar.

J Environ Manage 2019 Feb 15;231:1164-1175. Epub 2018 Nov 15.

College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Laboratory for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen, 518055, PR China. Electronic address:

Rational designing of metal-free carbon nitride based photocatalysts can lead to an excellent optical response and a higher photocatalytic activity driven by visible and solar light. This combines green photocatalytic technology with greener materials prepared by facile approaches for environmental remediation. Herein we report utilization of star photocatalyst g-CN (CN) to form highly efficient hetero-assemblies along with acidified g-CN (ACN), polyaniline (PANI), reduced graphene oxide (RGO) and biochar. By use of these organic semiconductors we synthesize g-CN/ACN/[email protected] (GARB), g-CN/PANI/[email protected] (GPRB) and ACN/PANI/[email protected] (APRB) nano-assemblies with different optical response and band edge positions for a better charge flow and reduced recombination of carriers. These synthesized catalysts were used for visible light powered degradation of 2,4-Dichlorophenoxy acetic acid (2,4-D) and ibuprofen (IBN). APRB performs the best and degrades 99.7% and 98.4% of 2,4-D and IBN (20 mg L) under Xe lamp exposure in 50 min and retention of high activity in natural sunlight. Optical analysis, photoelectrochemical response and radical quenching studies show both hydroxyl and superoxide radical anions as major reactive species and a Z-scheme photocatalytic mechanism. RGO acts as an electron mediator and protects higher positioned bands of PANI and ACN in APRB for a remarkable photocatalytic activity for a metal free material. The degradation pathway was analyzed by LC-MS analysis and 42% and 40% total organic carbon was removed in 2 h for 2,4-D and IBN degradation respectively. The toxicity of degraded products was analyzed by analyzing viability of human peripheral blood cells with retaining of 99.1% cells.
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http://dx.doi.org/10.1016/j.jenvman.2018.11.015DOI Listing
February 2019

Wide spectral degradation of Norfloxacin by [email protected]/BiOBr/BiFeO nano-assembly: Elucidating the photocatalytic mechanism under different light sources.

J Hazard Mater 2019 02 22;364:429-440. Epub 2018 Oct 22.

College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Laboratory for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen, 518055, PR China. Electronic address:

Metallic Ag deposited BiPO/BiOBr/BiFeO ternary nano-hetero-structures were rationally designed and synthesized by a simple precipitation-wet impregnation-photo deposition method. The plasmonic junction possesses an excellent wide spectrum photo-response and makes best use of BiPO which is otherwise a poor photocatalyst. [email protected]/BiOBr/BiFeO showed superior photocatalytic activity for degradation of norfloxacin (NFN) under visible, ultra-violet, near-infra-red and natural solar light. Especially catalyst APBF-3 (0.3 wt% [email protected]/BiOBr/BiFeO) shows 98.1% degradation of NFN (20 mg/L) in 90 min under visible light and 99.1% in less than 45 min under UV exposure. Free radical scavenging experiments and electron spin resonance (ESR) results has been used for explanation of charge transfer, photocatalytic mechanism and role of radicals for binary, ternary and Ag deposited ternary junctions for UV and visible exposure. Metallic Ag in addition to its surface plasmon resonance helps in protection of high conduction band and valence band in the three semiconductors. A dual Z-scheme mechanism has been predicted by comparing with possibilities of double charge and vectorial charge transfer.
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http://dx.doi.org/10.1016/j.jhazmat.2018.10.060DOI Listing
February 2019

Fabrication and characterization of Gum arabic-cl-poly(acrylamide) nanohydrogel for effective adsorption of crystal violet dye.

Carbohydr Polym 2018 Dec 5;202:444-453. Epub 2018 Sep 5.

College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab. for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060, PR China. Electronic address:

Natural biopolymers are better adsorbents due to better functionality, surface area, bio-compatibility and ease of procurement. The gum arabic in natural biopolymer derived from Acacia Arabic species. In the present work a novel nanohydrogel of gum arabic with acrylamide has been fabricated using microwave synthesis for adsorption of noxious crystal violet dye from aqueous medium. The prepared gum arabic-cl-poly(acrylamide) nanohydrogel (GA-cl-poly(AAm)) NHG was characterized by numerous techniques including SEM, XRD, TEM and FTIR. The GA-cl-poly(AAm) NHG showed promising adsorption ability for crystal violet dye. The effect of various adsorption factors such as concentration of GA-cl-poly(AAm) NHG and crystal violet, pH, temperature and time has been studied and reported. For understanding the adsorption mechanism three models Langmuir, Freundlich and Temkin were applied to adsorption data The kinetics and thermodynamics of adsorption were also investigated The adsorption capacity of crystal violet onto GA-cl-poly(AAm) NHG according to Langmuir model is found to be 90.90 mg/g.
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http://dx.doi.org/10.1016/j.carbpol.2018.09.004DOI Listing
December 2018

Guar gum and its composites as potential materials for diverse applications: A review.

Carbohydr Polym 2018 Nov 17;199:534-545. Epub 2018 Jul 17.

College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab. for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060, PR China. Electronic address:

Naturally occurring polymers are currently of prime importance among which polysaccharides occupies superior position due to their easy availability, eco- friendly and non-toxic nature. Guar gum, one of the naturally occurring polymer, is a galactomannan acquired by ground endosperm of Cyamopsis tetragonolobus or Cyamopsis psoraloides. It belongs to the family leguminosae. Presence of large number of hydroxyl groups increases its H- bonding ability when dissolved in water that enhance the viscosity and gelling properties of the guar gum solution. Based upon these properties, guar gum is used in several industries such as textile, food, petrochemical, mining and paper for varied applications. It is used as suspending, emulsifying, gelling and stabilising agent in the conventional dosage forms. Last few decades have marked the increase in development of various composites of guar gum that have intrinsic utilization in various fields. Immobilization of guar gum with the others not only enhances its properties but also enriches its utilization in numerous fields for diverse applications such as water purification, drug delivery, pharmaceutical, cosmetic and food industries, etc. Guar gum derivatives are found to have therapeutic importance in certain physiological disorders also. In this review article, we have summarized various possible composites of guar gum and their most probable applications in different fields.
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http://dx.doi.org/10.1016/j.carbpol.2018.07.053DOI Listing
November 2018

Cetyltrimethylammonium bromide intercalated and branched polyhydroxystyrene functionalized montmorillonite clay to sequester cationic dyes.

J Environ Manage 2018 Aug 9;219:285-293. Epub 2018 May 9.

Department of Chemical Engineering, Faculty of Engineering, Universitas Malikussaleh, Lhokseumawe-Aceh, Indonesia.

Herein, Cetyltrimethyl ammonium bromide (CTAB) intercalated and branched polyhydroxystyrene (BPS) functionalized montmorillonite (MMT) nano-composite (BPS-CTAB-MMT) was developed, characterized, and its potential as an adsorbent was tested in sequestering cationic dyes viz. rhodamine B (RB), crystal violet (CV), and methylene blue (MB) from aqueous environment. N adsorption/desorption isotherm showed mesoporous BPS-CTAB-MMT surface with a BET surface area of 273.8 m/g. The appearance of sharp spikes at 2855 and 2925 cm (associated with symmetric and asymmetric tensions of C - H bonds) in infra-red spectrum of BPS-CTAB-MMT indicates successful intercalation of MMT with CTAB and functionalization with BPS. The observed crystallite size of BPS-CTAB-MMT was 66 nm. Comparatively greater weight loss for BPS-CTAB-MMT (11%) than MMT (9%) was observed during thermogravimetric analysis. The adsorption of dyes on BPS-CTAB-MMT was pH dependent with maximum uptake was observed in the pH range: 5-6. For initial dyes concentration (C) range: 50-150 mg/L, the observed equilibration time for CV was 300 min, whereas for RB and MB the equilibration time varied between 300 and 360 min. Modeling investigations revealed the applicability of Sips isotherm and pseudo-second-order (PSO) kinetic models to dyes adsorption data. Sips maximum adsorption capacity (q) values for RB, CV, and MB at 55 °C were 476.5, 438.7, and 432.7 mg/g, respectively. The adsorption of dyes on BPS-CTAB-MMT was thermodynamically favorable. Desorption studies showed 42.1% RB and 41.9% CV recovery with 0.1 M NaOH and CHCOCH, respectively, while only traces of MB were recovered with tested eluents.
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http://dx.doi.org/10.1016/j.jenvman.2018.04.121DOI Listing
August 2018

Guar gum-crosslinked-Soya lecithin nanohydrogel sheets as effective adsorbent for the removal of thiophanate methyl fungicide.

Int J Biol Macromol 2018 Jul 20;114:295-305. Epub 2018 Mar 20.

College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab. for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060, PR China. Electronic address:

Rapid increase in use of fungicides for the agricultural and industrial purposes has marked the deterioration of water resources which ultimately affects the human life. Accordingly, various attempts have been made in the removal of these noxious compounds. In the same context, we are presenting biopolymers based nanohydrogel sheets; guar gum-crosslinked-Soya lecithin nanohydrogel sheets (GG-crosslinked-SY NHS) used for the effective removal of a fungicide; thiophanate methyl from aqueous solution. Guar gum and soya lecithin were employed as the biopolymers in the fabrication of nanohydrogel sheets due to their non- toxic nature, easy availability, cheapness and significant properties. Due to the presence of highly reactive functional groups onto the surface of GG-crosslinked-SY NHS, good adsorption results have been obtained. Maximum adsorption capacity of 59.205mg/g was observed with 20mg GG-crosslinked-SY NHS and 25ppm thiophanate methyl solution concentration as calculated from the Langmuir isotherm. Results showed that neutral pH favoured the adsorption process. Kinetics results were indicative of the physical interactions between the thiophanate methyl and GG-crosslinked-SY NHS surface. Thermodynamic results have shown the spontaneous and endothermic adsorption process.
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http://dx.doi.org/10.1016/j.ijbiomac.2018.03.093DOI Listing
July 2018

Novel Metal-Organic Framework (MOF) Based Composite Material for the Sequestration of U(VI) and Th(IV) Metal Ions from Aqueous Environment.

ACS Appl Mater Interfaces 2017 Oct 4;9(41):36026-36037. Epub 2017 Oct 4.

Department of Chemistry, College of Science, Building 5, King Saud University , Riyadh 11451, Kingdom of Saudi Arabia.

The combination of magnetic nanoparticles and metal-organic frameworks (MOFs) has demonstrated their prospective for pollutant sequestration. In this work, a magnetic metal-organic framework nanocomposite ([email protected](Al) was prepared and used for the removal of U(VI) and Th(IV) metal ions from aqueous environment. [email protected](Al) nanocomposite was characterized by TGA, FTIR, SEM-EDX, XRD, HRTEM, BET, VSM (vibrating sample magnetometry), and XPS analyses. A batch technique was applied for the removal of the aforesaid metal ions using [email protected](Al) at different operating parameters. The isotherm and kinetic data were accurately described by the Langmuir and pseudo-second-order models. The adsorption capacity was calculated to be 227.3 and 285.7 mg/g for U(VI) and Th(IV), respectively, by fitting the equilibrium data to the Langmuir model. The kinetic studies demonstrated that the equilibrium time was 90 min for each metal ion. Various thermodynamic parameters were evaluated which indicated the endothermic and spontaneous nature of adsorption. The collected outcomes showed that [email protected](Al) was a good material for the exclusion of these metal ions from aqueous medium. The adsorbed metals were easily recovered by desorption in 0.01 M HCl. The excellent adsorption capacity and the response to the magnetic field made this novel material an auspicious candidate for environmental remediation technologies.
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http://dx.doi.org/10.1021/acsami.7b10768DOI Listing
October 2017

Efficient removal of toxic phosphate anions from aqueous environment using pectin based quaternary amino anion exchanger.

Int J Biol Macromol 2018 Jan 31;106:1-10. Epub 2017 Jul 31.

Department of Chemistry, College of Science, Building#5, King Saud University, Riyadh-11451, Saudi Arabia.

Pectin based quaternary amino anion exchanger (Pc-QAE) was prepared using simple crosslinking polymerization method. This anion exchanger was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Pc-QAE was applied for the removal of phosphate anion from the aqueous solution. The adsorption process which was pH dependent showed maximum adsorption of phosphate anions at pH 7. Pc-QAE showed good monolayer adsorption capacity for phosphate anions which demonstrated its good capability towards Langmuir isotherm model. Moreover, the adsorption was evaluated thermodynamically and the negative value of Gibbs free energy (-1.791KJ/mol) revealed the spontaneity of adsorption process. The value of ΔH° and ΔS° were found to be 15.28 and 49.48KJ/mol, respectively representing the endothermic nature and enhancement in degree of freedom due to the adsorption process.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.07.169DOI Listing
January 2018

Determination of heavy metals in skin-whitening cosmetics using microwave digestion and inductively coupled plasma atomic emission spectrometry.

IET Nanobiotechnol 2017 Aug;11(5):597-603

Department of Chemistry, College of Science, Bld#5, King Saud University, Riyadh, Saudi Arabia.

In this study, the determination of noxious heavy metals, cadmium (Cd), bismuth (Bi), mercury (Hg), titanium (Ti), lead (Pb) and metalloid arsenic (As) in skin-whitening cosmetics were examined using microwave digestion and inductively coupled plasma atomic emission spectrometry method. A complete digestion of cosmetics samples was achieved using a mixture of hydrofluoric acid/hydrogen peroxide/nitric acid. The quantification of the target compounds was done by standard addition method. The excellent quality parameters for instance, detection limits, As (4.6 ppb), Bi (7.9 ppb), Cd (0.45 ppb), Hg (3.3 ppb), Pb (3.8 ppb), Ti (4.3 ppb), linearity ( > 0.999) and run-to-run and day-to-day precisions with relative standard deviations <3% were obtained. The recovery rates for standard reference materials were found between 90 and 105%. The average concentration of heavy metals in cosmetics samples were in the range of 1.0-12.3 (μg g, As), 33-7097 (μg g, Bi), 0.20-0.6 (μg g, Cd), 0.70-2700 (μg g, Hg), 1.20-143 (μg g, Pb) and 2.0-1650 (μg g, Ti).
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http://dx.doi.org/10.1049/iet-nbt.2016.0212DOI Listing
August 2017

ZnSe-WO nano-hetero-assembly stacked on Gum ghatti for photo-degradative removal of Bisphenol A: Symbiose of adsorption and photocatalysis.

Int J Biol Macromol 2017 Nov 1;104(Pt A):1172-1184. Epub 2017 Jul 1.

Department of Chemistry, College of Science, Building#5, King Saud University, Riyadh, 11451, Saudi Arabia.

In this research work we report Gum-ghatti supported ZnSe-WO nano-hetero-assembly for solar powered degradation of endocrine disruptor Bisphenol S (BPA). The photocatalyst was characterized by Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM), Small area electron diffraction (SAED), X-Ray diffraction (XRD), Fourier transform infra red spectroscopy (FTIR), Photoluminescence (PL), Energy dispersive X-ray (EDX), UV-vis spectrophotometry and Brauner Emmet Teller surface area analyzer (BET). We achieve a Z-scheme photocatalyst (ZnSe-WO) with a higher charge flow and visible absorption. Gum ghatti acts as a superadsorbent and a sink for charge carriers. The removal of BPA has been studied under three experimental protocols where 99.5% removal was achieved by symbiose of photocatalysis-adsorption-ozonation in just 45min hetero-assembly has a high surface area, stability and reduced carrier recombination. The results have been analyzed by scavenger effect, mass spectrometry, kinetics and total organic carbon (TOC) analysis. 49.4% of TOC was removed and COD was reduced to 16.7% after 2h in symbiotic condition. From the band edges and scavenger effect it was inferred that superoxide radical anions are major attacking species. The work paves way for designing of novel photocatalysts with increasing biogenic quotient and higher efficiency.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.06.116DOI Listing
November 2017

Efficient photocatalytic degradation of toxic dyes from aqueous environment using gelatin-Zr(IV) phosphate nanocomposite and its antimicrobial activity.

Colloids Surf B Biointerfaces 2017 Sep 20;157:456-463. Epub 2017 Jun 20.

Department of Chemistry, College of Science, Bld.#5, King Saud University, Riyadh, Saudi Arabia. Electronic address:

In the present study, gelatin-Zr(IV) phosphate nanocomposite (GT/ZPNC) was synthesized by sol-gel method by mixing the gelatin gel into the inorganic part Zr (IV) phosphate (ZP). The GT/ZPNC was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), transmission electron micron scope (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The photodegradation activity of GT/ZPNC was explored for the removal of methylene blue (MB) and fast green (FG) dyes from aqueous solution. It was found that 87.81% MB and 89.91% FG were degraded within five hours. Also, the kinetics of photocatalytic degradation for MB and FG was investigated via pseudo first-order kinetic model with higher regression coefficient values (R). The antimicrobial efficiency of GT/ZPNC was investigated against E. coli.
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http://dx.doi.org/10.1016/j.colsurfb.2017.06.018DOI Listing
September 2017

Remediation of anionic dye from aqueous system using bio-adsorbent prepared by microwave activation.

Environ Technol 2018 Apr 21;39(7):917-930. Epub 2017 Apr 21.

a School of Chemistry , Shoolini University , Solan , India.

The present study was attempted to ascertain the possible application of activated carbon as a cost-effective and eco-friendly adsorbent prepared via microwave-assisted chemical activation. The activated carbon was characterized using different techniques. The various adsorption parameters have been optimized to examine the viability of activated carbon as a plausible sorbent for the remediation of Congo red (CR) dye from the aquatic system. The equilibrium data adequately fitted to the Langmuir isotherm with better R (0.994). The maximum adsorption capacity (q) of activated carbon was recorded to be 68.96 mg/g. Additionally, sorptional kinetic data were examined by reaction-based and diffusion-based models such as pseudo-first-order and pseudo-second-order equations, and Elovich, intra-particle diffusion, and Dumwald-Wagner models, respectively. The computed values of thermodynamic parameters such as free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were recorded as -3.63, 42.47 and 152.07 J/mol K, respectively, at 30°C, which accounted for a favorable, spontaneous and endothermic process. The regeneration study emphasized that the percentage uptake declined from 90.35% to 83.45% after six cycles of testing. So, our findings implied that activated carbon produced from biomass must be cost-effectively used as an adsorbent for detoxifying the CR dye from industrial effluents.
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http://dx.doi.org/10.1080/09593330.2017.1317293DOI Listing
April 2018

Correlation between vitamin D levels and apoptosis in geriatric patients infected with hepatitis C virus genotype 4.

Clin Interv Aging 2016 4;11:523-33. Epub 2016 May 4.

Internal Endemic Medicine Department, College of Medicine, Beni-Suef University, Beni Suef, Egypt.

Background: Vitamin D levels play a pivotal role in most biological processes and differ according to age. A deficiency of vitamin D in chronic hepatitis C (CHC) patients has been shown to be linked with the severity of liver fibrosis, but little is known about the mechanism of this association.

Objective: In this study, we evaluate the potential interrelation between vitamin D levels, oxidative stress, and apoptosis, based on liver fibrosis in geriatric patients infected with hepatitis C virus (HCV) genotype 4.

Subjects And Methods: A total of 120 adult individuals aged 30-68 years were recruited in this study. Of these, 20 healthy subjects (15 men and five women) with a mean age of 48.3±6.1 years were selected as controls, and 100 patients with a mean age of 47.8±4.9 years with chronic HCV (CHC) who had undergone liver biopsy (80 men and 20 women) were included in this study. Based on liver radiographic (computed tomography, magnetic resonance imaging) and histological Metavir system analyses, the CHC patients were classified into three groups: asymptomatic CHC carriers (n=30), fibrosis (n=25), and cirrhosis (n=45). HCV RNA, HCV genotypes, inflammatory cytokines AFP and TNFα, 25-hydroxyvitamin D (25[OH]D) levels, apoptotic markers single-stranded DNA (ssDNA) and soluble Fas (sFas), and oxidative stress markers nitric oxide (NO) and total antioxidant capacity (TAC) were estimated by using molecular, immunoassay, and colorimetric techniques.

Results: Approximately 30% of the study population (n=30) were diagnosed as asymptomatic CHC carriers, and 70% of the study population (n=70) had severe fibrosis; these were classified into fibrosis and cirrhosis. There was a significant reduction in 25(OH)D levels and TAC activity, along with an increase in levels of NO, AFP, TNFα, ssDNA, and sFas in fibrosis and cirrhosis subjects compared with those of asymptomatic CHC carriers and health controls. The deficiency in 25(OH)D levels correlated positively with sFas, ssDNA, AFP, TNFα, NO, and TAC, and negatively with age, sex, liver function, body mass index, homeostatic model assessment - insulin resistance, HCV RNA, and viral load. Significant intercorrelation was reported between serum 25(OH)D concentrations and apoptotic and oxidative markers, which suggested progression of liver pathogenesis and fibrogenesis via oxidative and apoptotic mechanisms.

Conclusion: The data showed that vitamin D status was significantly correlated with pathogenesis and fibrogenesis of the liver in geriatric patients infected with HCV genotype 4. The deficiency in 25(OH)D levels was shown to have a pivotal role in the pathogenesis of liver via apoptotic, oxidative stress, and inflammatory mechanistic pathways. The data point to adequate vitamin D levels being recommended for a good response to treatment strategies, especially in older CHC patients.
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http://dx.doi.org/10.2147/CIA.S104599DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862759PMC
January 2018

Simultaneous determination of monosaccharides and oligosaccharides in dates using liquid chromatography-electrospray ionization mass spectrometry.

Food Chem 2015 Jun 17;176:487-92. Epub 2014 Dec 17.

Department of Chemistry, College of Science, Princess Nora Bint Abdulrahman University, P.O. Box 84428, 11671 Riyadh, Saudi Arabia.

Ultra performance liquid chromatography coupled to mass spectrometry was used for the simultaneous separation and determination of reducing monosaccharides (fructose and glucose), a non-reducing disaccharide (sucrose) and oligosaccharides (kestose and nystose) in HILIC mode. The chromatographic separation of all saccharides was performed on a BEH amide column using an acetonitrile-water gradient elution. The detection was carried out using selected ion recording (SIR) acquisition mode. The validation of the proposed method showed that the limit of detection and limit of quantification values for the five analyzed compounds were in the range of 0.25-0.69μg/mL and 0.82-3.58μg/mL, respectively; while the response was linear in the range of 1-50μg/mL. The developed method showed potential usefulness for a rapid and sensitive analysis of underivatized saccharides and was used for determination of sugars in three date samples (Sefri, Mabroom, Ghassab) which were soxhlet extracted by ethanol.
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http://dx.doi.org/10.1016/j.foodchem.2014.12.035DOI Listing
June 2015

Analysis of aflatoxins in nonalcoholic beer using liquid-liquid extraction and ultraperformance LC-MS/MS.

J Sep Sci 2013 Feb 4;36(3):572-7. Epub 2012 Dec 4.

Advanced Materials Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.

Aflatoxins AFB1, AFB2, AFG1, and AFG2 are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus and posses a potential threat to food safety. In the present work, liquid-liquid extraction and ultraperformance LC-MS/MS method has been applied for the determination of four naturally occurring aflatoxins AFB1, AFB2, AFG1, and AFG2 in nonalcoholic beer. Aflatoxins extraction from nonalcoholic beer was carried out using liquid-liquid extraction procedure. The effects of solvent-types were studied to obtain maximum recovery of the target analytes with minimum contamination. Among different solvents, the aflatoxins extraction was best achieved using ethyl acetate. The obtained recoveries were ranged from 85 to 96% with good quality parameters: LOD values between 0.001 and 0.003 ng/mL, linearity of the calibration curve (r(2) > 0.999), and repeatability (run-to-run) and reproducibility (day-to-day) precisions with RSDs lower than 5% (n = 5) achieved at 0.50 ng/mL concentration. The optimized liquid-liquid extraction in combination with ultraperformance LC-MS/MS was applied successfully to the analysis of AFB1, AFB2, AFG1, and AFG2 aflatoxins in 11 nonalcoholic beers and were detected up to 15.31 ng/L in some of the samples.
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http://dx.doi.org/10.1002/jssc.201200752DOI Listing
February 2013
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