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1.
Prep Biochem Biotechnol ; 54(3): 294-306, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37452678

RESUMO

In this investigation, two new thermophilic bacteria were isolated. The new isolates were characterized by 16S rRNA, biochemical, morphological, and physiological analyzes and the isolates were identified as Geobacillus stearothermophilus strain Gecek20 and thermophilic Anoxybacillus flavithermus strain Gecek19. Various biological activities of extracellular Ag-NPs synthesized from thermophilic G. stearothermophilus strain Gecek20 and thermophilic A. flavithermus strain Gecek19 were evaluated. The produced NPs were analyzed by SEM, SEM-EDX, and XRD analyses. The antioxidant abilities of new synthesized Ag-NPs from thermophilic G. stearothermophilus strain Gecek20 (T1-Ag-NPs) and new synthesized Ag-NPs from thermophilic A. flavithermus strain Gecek19 (T2-Ag-NPs) were studied by DPPH inhibition and metal chelating ability. The highest DPPH and metal chelating abilities of T1-Ag-NPs and T2-Ag-NPs at 200 mg/L concentration were 93.17 and 90.85%, and 75.80 and 83.64%, respectively. The extracellular green synthesized T1-Ag-NPs and T2-AgN-Ps showed DNA nuclease activity at all tested concentrations. Moreover, both new synthesized Ag-NPs had antimicrobial activity against the strains studied, especially on Gram positive bacteria. T1-Ag-NPs and T2-AgNPs also showed powerful Escherichia coli growth inhibition. The highest biofilm inhibition percentages of T1-Ag-NPs and T2-Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus were 100.0%, respectively, at 500 mg/L.


Assuntos
Anoxybacillus , Geobacillus stearothermophilus , Nanopartículas Metálicas , RNA Ribossômico 16S , Prata/farmacologia , Escherichia coli
2.
Environ Res ; 238(Pt 1): 117166, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37741570

RESUMO

Tofacitinib (TOF) is gaining recognition as a potent therapeutic agent for a variety of autoimmune disorders, including rheumatoid arthritis and psoriasis. Ensuring precise drug concentration control during treatment necessitates a rapid and sensitive detection method. This study introduces a novel electrochemical sensor employing a composite of nanodiamond (ND), copper aluminate spinel oxide (CuAl2O4), and iron (II, III) oxide (Fe3O4) as modified materials for efficient TOF detection. Extensive analyses using physicochemical and electrochemical techniques were carried out to characterize the morphological, structural, and electrochemical properties of the ND@CuAl2O4@Fe3O4 composite. Thereafter, various voltammetric methods were utilized to evaluate the electrochemical behavior of the ND@CuAl2O4@Fe3O4-modified glassy carbon electrode (GCE) concerning TOF determination. The fabricated electrode showcased superior performance in electrochemical TOF detection in a buffered solution (pH = 5), achieving a remarkably low detection limit of 7.8 nM and a linear response from 0.05 µM to 13.21 µM. Furthermore, applying the modified electrode as an electrochemical sensor exhibited exceptional selectivity, stability, and practicality in determining TOF in pharmaceutical and biological samples. Alongside the sensor development, this study conducted a thorough investigation using Density Functional Theory (DFT) for the geometry optimization of TOF and the TOF-ND complex. Consequently performed molecular docking studies using Janus Kinase 1 (JAK1) (PDB ID: 3EYG) and JAK3 (PDB ID: 3LXK) indicated higher interaction of the TOF-ND conjugate with the JAKs, reflected by binding energies of -12.9 kcal/mol and -11.7 kcal/mol for JAK1 and JAK3 respectively, compared to -7.0 kcal/mol and -6.9 kcal/mol for TOF alone. These findings illustrate the potential of the ND-based ND@CuAl2O4@Fe3O4 composite as a proficient sensing material for TOF detection and the merits of DFT in providing a detailed understanding of the interactions at play. This pioneering research holds promise for real-time TOF monitoring, which will advance personalized treatment strategies and improve therapeutic outcomes for patients with autoimmune disorders.


Assuntos
Doenças Autoimunes , Grafite , Nanodiamantes , Humanos , Grafite/química , Simulação de Acoplamento Molecular , Limite de Detecção , Carbono/química , Óxidos/química
3.
J Sep Sci ; 46(19): e2300190, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37496320

RESUMO

An NH2 -MIL-53(Al)-DES(ChCl-Urea) nanocomposite was synthesized for extraction and determination of Rhodamine (Rh) 6G from environmental and cosmetic samples. The deep eutectic solvent (DES) was prepared by mixing choline chloride and urea in a mole ratio of 1:2. NH2 -MIL-53(Al)-DES(ChCl-Urea) nanocomposite was synthesized using the impregnation method at a ratio of 60:40 (w/w). The optimum conditions were determined after NH2 -MIL-53(Al)-DES(ChCl-Urea) characterization was performed. The optimum conditions were determined as pH 8, adsorbent amount of 15 mg, total adsorption-desorption time of 6 min, and enrichment factor of 20. The recovery values of the solid-phase extraction method for water and cosmetic samples under optimum conditions were between 95% and 106%. NH2 -MIL-53(Al)-DES(ChCl-Urea) nanocomposite was an economically advantageous adsorbent because of its reusability of 15 times. All analyses were performed using the ultraviolet-visible spectrophotometer. The linear range, limit of detection, and limit of quantification of the method were 100-1000, 9.80, and 32.68 µg/L, respectively. The obtained results showed that the synthesized nanocomposite is a suitable adsorbent for the determination of Rh 6G in water and cosmetic samples. The real sample applications were verified with the high-performance liquid chromatography system.

4.
Mikrochim Acta ; 190(4): 142, 2023 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-36933052

RESUMO

The present study aims to develop an electroanalytical method to determine one of the most significant antineoplastic agents, topotecan (TPT), using a novel and selective molecular imprinted polymer (MIP) method for the first time. The MIP was synthesized using the electropolymerization method using TPT as a template molecule and pyrrole (Pyr) as the functional monomer on a metal-organic framework decorated with chitosan-stabilized gold nanoparticles (Au-CH@MOF-5). The materials' morphological and physical characteristics were characterized using various physical techniques. The analytical characteristics of the obtained sensors were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). After all characterizations and optimizing the experimental conditions, MIP-Au-CH@MOF-5 and NIP-Au-CH@MOF-5 were evaluated on the glassy carbon electrode (GCE). MIP-Au-CH@MOF-5/GCE indicated a wide linear response of 0.4-70.0 nM and a low detection limit (LOD) of 0.298 nM. The developed sensor also showed excellent recovery in human plasma and nasal samples with recoveries of 94.41-106.16 % and 95.1-107.0 %, respectively, confirming its potential for future on-site monitoring of TPT in real samples. This methodology offers a different approach to electroanalytical procedures using MIP methods. Moreover, the high sensitivity and selectivity of the developed sensor were illustrated by the ability to recognize TPT over potentially interfering agents. Hence, it can be speculated that the fabricated MIP-Au-CH@MOF-5/GCE may be utilized in a multitude of areas, including public health and food quality.


Assuntos
Quitosana , Nanopartículas Metálicas , Estruturas Metalorgânicas , Impressão Molecular , Humanos , Polímeros Molecularmente Impressos , Quitosana/química , Topotecan , Ouro/química , Nanopartículas Metálicas/química , Técnicas Eletroquímicas/métodos , Impressão Molecular/métodos , Limite de Detecção , Polímeros/química , Carbono/química
5.
Environ Res ; 209: 112766, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35085567

RESUMO

For the simultaneous preconcentrations of Cu(II) and Mn(II), a novel preconcentration technique was developed and described. Bacillus cereus loaded magnetic É£-Fe2O3 nanoparticles were prepared and used as support materials on solid-phase extraction procedure. Important experimental parameters were investigated in details and pH 6.0, 3 mL min-1 of flow rate, 5 mL of 1 mol L-1 of HCl as eluent, 200 mg of biomass, and 200 mg of magnetic É£-Fe2O3 nanoparticles as support material was found as the best conditions. The preconcentrations factor were found to be 80 for Cu (II) and Mn(II). It was confirmed by the results that SPE columns could be used in 32 cycles. The LOD values calculated for Cu (II) and Mn (II) were 0.09 and 0.08 ng mL-1, respectively. The RSD values found were less than 3.4%. The extraction recoveries were achieved as higher than 98%. The biosorption capacities of Cu (II), and Mn (II) were 26.0 mg g-1, 30.3 mg g-1 respectively. The approach devised for analyzing analyte concentrations in food samples proved to be successful.


Assuntos
Bacillus cereus , Nanopartículas , Adsorção , Fenômenos Magnéticos , Extração em Fase Sólida/métodos
6.
Environ Monit Assess ; 194(8): 591, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35844019

RESUMO

Antimony (Sb) is highly hazardous to human health even in minute concentration. Therefore, its accurate and precise determination in the real environmental samples is of immense importance. In this work for the first time, UV-Vis spectrophotometric method was developed for the quantification of Sb(III) from water samples using supramolecular solvent (undecanol-tetrahydrofuran)-based extraction. The maximum absorption wavelength for antomony-diathizone complex was found to be 590 nm having molar absorptivity of 3.1 × 104 L.mol.cm-1. Factors affecting extraction efficiency like solution sample volume, amount of chelating agent, pH, matrix effect, and type and volume of supramolecular solvent were determined and optimized. Analytical parameters like limit of detection (0.19 µg L-1), limit of quantification (0.62 µg L-1), pre-concentration factor (15), enhancement factor (15), and relative standard deviation for 8 successive analysis (0.8%) were calculated under optimized experimental conditions. The method was applied to real water samples like tap water of laboratory, waste water from Kohat hospitals, and dam water (Tanda dam Kohat) with quantitative addition recovery (94-100%).


Assuntos
Antimônio , Microextração em Fase Líquida , Antimônio/análise , Monitoramento Ambiental/métodos , Humanos , Microextração em Fase Líquida/métodos , Extração Líquido-Líquido , Solventes/química
7.
Environ Monit Assess ; 194(8): 526, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739281

RESUMO

The mobility of potentially toxic elements (PTEs) is of paramount concern in urban settings, particularly those affected by industrial activities. Here, contaminated soils and road dusts of the medium-size, industrialized city of Volos, Central Greece, were subjected to single-step extractions (0.43 M HNO3 and 0.5 M HCl) and the modified BCR sequential extraction procedure. This approach will allow for a better understanding of the geochemical phase partitioning of PTEs and associated risks in urban environmental matrices. Based on single extraction procedures, Pb and Zn exhibited the highest remobilization potential. Of the non-residual phases, the reducible was the most important for Pb, and the oxidizable for Cu and Zn in both media. On the other hand, mobility of Ni, Cr, and Fe was low, as inferred by their dominance into the residual fraction. Interestingly, we found a significant increase of the residual fraction in the road dust samples compared to soils. Carbonate content and organic matter controlled the extractabilities of PTEs in the soil samples. By contrast, for the road dust, magnetic susceptibility exerted the main control on the geochemical partitioning of PTEs. We suggest that anthropogenic particles emitted by heavy industries reside in the residual fraction of the SEP, raising concerns about the assessment of this fraction in terms of origin of PTEs and potential environmental risks. Conclusively, the application of sequential extraction procedures should be complemented with source identification of PTEs with the aim to better estimate the remobilization of PHEs in soil and road dust influenced by industrial emissions.


Assuntos
Metais Pesados , Poluentes do Solo , Cidades , Poeira/análise , Monitoramento Ambiental/métodos , Chumbo , Metalurgia , Metais Pesados/análise , Medição de Risco , Solo/química , Poluentes do Solo/análise
8.
Anal Biochem ; 617: 114122, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33515499

RESUMO

In this study, we present an environmental friend and easy procedure for simultaneous preconcentration of Cr(III), Hg(II) and Zn(II) by solid-phase extraction before their determination by inductively coupled plasma optical emission spectrometry. Armillae mellea immobilized nanodiamond was used as sorbent. During the study, critical parameters influencing the extraction performance were investigated in detail. The best parameters were found as pH 5.0, 2.0 mL min-1 of flow rate, 200 mg of Armillae mellea, 300 mL of sample volume. LOD values were found as 0.025, 0.13 and 0.038 ng mL-1, respectively for Cr(III), Hg(II) and Zn(II). By applying the developed procedure, sensitivities of ICP-OES were improved for 60 fold for Cr(III), Hg(II) and Zn(II). Their concentrations in different food samples were measured after microwave digestion and solid-phase extraction.


Assuntos
Cromo/química , Mercúrio/química , Nanodiamantes/química , Zinco/química , Extração em Fase Sólida
9.
Anal Bioanal Chem ; 413(4): 1107-1116, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33388846

RESUMO

This paper proposes the use of Anoxybacillus flavithermus SO-15 immobilized on iron oxide nanoparticles (NPs) as a novel magnetized biosorbent for the preconcentrations of uranium (U) and thorium (Th). The SPE procedure was based on biosorption of U(VI) and Th(IV) on a column of iron oxide NPs loaded with dead and dried thermophilic bacterial biomass prior to U(VI) and Th(IV) measurements by ICP-OES. The biosorbent characteristicswere explored using FT-IR, SEM, and EDX. Significant operational factors such as solution pH, volume and flow rate of the sample solution, amounts of dead bacteria and iron oxide nanoparticles, matrix interference effect, eluent type, and repeating use of the biosorbent on process yield were studied. The biosorption capacities were found as 62.7 and 56.4 mg g-1 for U(VI) and Th(IV), respectively. The novel extraction process has been successfullyapplied to the tap, river, and lake water samples for preconcentrations of U(VI) and Th(IV).


Assuntos
Anoxybacillus/química , Nanopartículas Magnéticas de Óxido de Ferro/química , Extração em Fase Sólida/métodos , Tório/isolamento & purificação , Urânio/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Células Imobilizadas/química
10.
Mikrochim Acta ; 188(3): 102, 2021 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-33638711

RESUMO

Metastable and rarely reported GO warped tetragonal phase t-lanthanum vanadate nanocomposites (GO@LaVO4-NCs) are reported for the sensitive electrochemical determination of antifungal drug Clioquinol (CQ). The hydrothermal method was adopted for synthesis of GO@LaVO4-NCs. The electrochemical performance of CQ was examined using cyclic voltammetry (CV) and differential plus voltammetry (DPV) at GO@LaVO4-NCs modified glassy carbon electrode (GCE). The electrocatalytic oxidation of CQ at the GO@LaVO4-NCs/GCE shows the highest anodic peak current at a potential of +0.51 V vs. Ag/AgCl. The proposed sensor provides excellent sensitivity of 4.1894 µA µM-1 cm-2, a very low detection limit (LOD) of 2.44 nM, and a wide range of 25 nM to 438.52 µM towards CQ detection. Finally, the detection of CQ in biological media was successfully done using the GO@LaVO4-NCs/GCE and possesses recoveries of 94.67-98.0%.


Assuntos
Antifúngicos/análise , Antiprotozoários/análise , Clioquinol/análise , Técnicas Eletroquímicas/métodos , Nanocompostos/química , Antifúngicos/sangue , Antifúngicos/química , Antifúngicos/urina , Antiprotozoários/sangue , Antiprotozoários/química , Antiprotozoários/urina , Clioquinol/sangue , Clioquinol/química , Clioquinol/urina , Grafite/química , Humanos , Lantânio/química , Limite de Detecção , Oxirredução , Reprodutibilidade dos Testes , Vanadatos/química
11.
J Sep Sci ; 43(15): 3103-3109, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32463175

RESUMO

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.

12.
Molecules ; 25(20)2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33086622

RESUMO

Microextraction procedures for the separation of Pb(II) from water and food samples extracts were developed. A deep eutectic solvent composed of α-benzoin oxime and iron(III) chloride dissolved in phenol was applied as a phase separator support. In addition, this deep eutectic mixture worked as an efficient extractor of Pb(II). The developed microextraction process showed a high ability to tolerate the common coexisting ions in the real samples. The optimum conditions for quantitative recoveries of Pb(II) from aqueous extracts were at pH 2.0, conducted by adding 150 µL from the deep eutectic solvent. The quantitative recoveries were obtained with various initial sample volumes up to 30 mL. Limits of detection and limits of quantification of 0.008 and 0.025 µg L-1 were achieved with a relative standard deviation (RSD%) of 2.9, which indicates the accuracy and sensitivity of the developed procedure. Recoveries from the reference materials, including TMDA 64.2, TMDA 53.3, and NCSDC-73349, were 100%, 97%, and 102%, respectively. Real samples, such as tap, lake, and river water, as well as food samples, including salted peanuts, chickpeas, roasted yellow corn, pistachios, and almonds, were successfully applied for Pb(II) analysis by atomic absorption spectroscopy (AAS) after applying the developed deep eutectic solvent-based microextraction procedures.


Assuntos
Compostos Férricos/isolamento & purificação , Chumbo/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Água/química , Animais , Compostos Férricos/química , Contaminação de Alimentos , Humanos , Chumbo/toxicidade , Limite de Detecção , Microextração em Fase Líquida , Leite/química , Espectrofotometria Atômica , Poluentes Químicos da Água/química
13.
Mikrochim Acta ; 186(10): 666, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31482367

RESUMO

A MWCNT@MoSe2 nanorod hybrid material was synthesized by a hydrothermal method and used as an adsorbent for trace levels of Pb(II) and Cu(II). The material was characterized by Raman spectroscopy, XRD, SEM, SEM-EDX, SEM-mapping and BET methods. The hybrid material is demonstrated to be a viable sorbent for ultrasound-assisted solid phase extraction of Pb(II) and Cu(II) at pH 5.5. Following desorption with 3 M HNO3, the two elements were quantified by FAAS. Key parameters affecting the extraction efficiency, including eluent conditions, amount of adsorbent, sample volume were optimized. No significant interference by other ions is observed. The accuracy of the method was evaluated by the analysis of the certified reference materials TMDA-53.3 (lake water) and SPS-WW2 (waste water level 2). The recoveries were in good agreement with certified values. The method was successfully applied to the extraction/preconcentration of Pb(II) and Cu(II) in different real samples. Graphical abstract A hybrid material of type MWCNT@MoSe2 was synthesized, characterized, and used as adsorbent for Pb(II) and Cu(II). Key parameters affecting the extraction efficiency, including eluent conditions, amount of adsorbent, sample volume were optimized. The method was applied to the extraction of analytes in water samples.

14.
Mikrochim Acta ; 186(6): 355, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31098920

RESUMO

The fungus Bovista plumbea immobilized on γ-Fe2O3 nanoparticles is shown to be a novel sorbent for magnetic solid-phase extractions of U(VI) and Th(IV). The biosorbent was characterized by FT-IR, SEM, and EDX. The effects of pH value, flow rate and volume of sample, amounts of biomass and support material, eluent type, foreign ions and repeated use of the sorbent on extraction efficiency were investigated. The sorption capacities are 41 and 44 mg g-1, respectively, for U(VI) and Th(IV). The results indicated that B. plumbea immobilized onto γ-Fe2O3 nanoparticles can be utilized as a novel material for the preconcentrations of U(VI) and Th(IV) in certified materials and in spiked tap, river and lake waters. Graphical abstract Schematic presentation of a method for preconcentrations of Th(IV) and U(VI) ions using γ-Fe2O3 nanoparticles loaded with the fungus Bovista plumbea.


Assuntos
Basidiomycota/química , Poluentes Ambientais/análise , Óxido Ferroso-Férrico/química , Nanopartículas de Magnetita/química , Extração em Fase Sólida , Tório/análise , Urânio/análise , Análise Espectral
15.
Mikrochim Acta ; 185(1): 34, 2017 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-29594546

RESUMO

Nanosized single crystal orthorhombic Bi2WO6 was synthesized by a hydrothermal method and used as a sorbent for vortex assisted solid phase extraction of lead(II). The crystal and molecular structure of the sorbent was examined using XRD, Raman, SEM and SEM-EDX analysis. Various parameters affecting extraction efficiency were optimized by using multivariate design. The effect of diverse ions on the extraction also was studied. Lead was quantified by flame atomic absorption spectrometry (FAAS). The recoveries of lead(II) from spiked samples (at a typical spiking level of 200-400 ng·mL-1) are >95%. Other figures of merit includes (a) a detection limit of 6 ng·mL-1, (b) a preconcentration factor of 50, (c) a relative standard deviation of 1.6%, and (d) and adsorption capacity of 6.6 mg·g-1. The procedure was successfully applied to accurate determination of lead in (spiked) pomegranate and water samples. Graphical abstract Nanosized single crystal orthorhombic Bi2WO6 was synthesized and characterized by a hydrothermal method and used as a sorbent for vortex assisted solid phase extraction of lead(II). The procedure was successfully applied to accurate determination of lead in (spiked) pomegranate and water samples.

16.
Mikrochim Acta ; 185(1): 73, 2017 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-29594597

RESUMO

The authors show that the fungus Boletus edulis loaded with γ-Fe2O3 nanoparticles is a viable sorbent for magnetic solid phase extraction of trace levels of Co(II) and Sn(II). The surface structure of immobilized magnetized B. edulis was characterized by FT-IR, SEM and EDX. Experimental parameters were optimized. Following elution with 1 M HCl, the ions were quantified by ICP-OES. The limits of detection are 21 pg·mL-1 for Co(II), and 19 pg·mL-1 for Sn(II). The preconcentration factors are 100 for both ions. The sorption capacities of the sorbent are 35.8 mg·g-1 for Co(II) and 29.6 mg·g-1 for Sn(II). The method was applied to the analysis of certificated reference materials and gave ≥95% recoveries with low RSDs. It was also successfully applied to the quantification of Co(II) and Sn(II) in spiked environmental and food samples. Graphical abstract The fungus Boletus edulis loaded with γ-Fe2O3 nanoparticles is a viable biosorbent for magnetic solid phase extraction (MSPE) of trace levels of Co(II) and Sn(II). The surface structure of immobilized magnetized B. edulis was characterized by FT-IR, SEM and EDX. Experimental parameters were optimized.

17.
J Environ Manage ; 187: 490-496, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27856038

RESUMO

In this study, uranium(VI) tolerance and bioaccumulation were investigated by using thermo -tolerant Bacillus mojavensis. The level of U(VI) was measured by UV-VIS spectrophotometry. The minimum inhibition concentration (MIC) value of U(VI) was experimented. Bacterial growth was not affected in the presence of 1.0 and 2.5 mg/L U(VI) at 36 h and the growth was partially affected in the presence of 5 mg/L U(VI) at 24 h. What was obtained from this study is that there was diversity in the various periods of the growth phases of metal bioaccumulation capacity, which was shown by B. mojavensis. The maximum bioaccumulation capacities were found to be 12.8, 22.7, and 48.2 mg/g dried bacteria, at 24th hours at concentration of 1.0, 2.5 and 5 mg/L U(VI), respectively. In addition to these, U(VI) has been preconcentrated on B. mojavensis immobilized MWCNT. Several factors such as pH, flow rate of solution, amount of biosorbent and support materials, eluent type, concentration and volume, the matrix interference effect on retention have been studied, and extraction conditions were optimized. Preconcentration factor was achieved as 60. Under the optimized conditions, the limit of detection (LOD) and quantification (LOQ) were calculated as 0.74 and 2.47 µg/L. The biosorption capacity of immobilized B. mojavensis was calculated for U(VI) as 25.8 mg/g. The results demonstrated that the immobilized biosorbent column could be reused at least 30 cycles of biosorption and desorption with the higher than 95% recovery. FT-IR and SEM analysis were performed to understand the surface properties of B. mojavensis.


Assuntos
Bacillus/metabolismo , Reatores Biológicos , Nanotubos de Carbono , Radioisótopos/metabolismo , Urânio/metabolismo , Cátions , Humanos , Resíduos Sólidos , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Bull Environ Contam Toxicol ; 99(2): 264-269, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28321470

RESUMO

In the present study, a simple, mono step deep eutectic solvent (DES) extraction was developed for selective extraction of copper from sediment samples. The optimization of all experimental parameters, e.g. DES type, sample/DES ratio, contact time and temperature were performed with using BCR-280 R (lake sediment certified reference material). The limit of detection (LOD) and the limit of quantification (LOQ) were found as 1.2 and 3.97 µg L-1, respectively. The RSD of the procedure was 7.5%. The proposed extraction method was applied to river and lake sediments sampled from Serpincik, Çeltek, Kizilirmak (Fadl and Tecer region of the river), Sivas-Turkey.


Assuntos
Cobre/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Limite de Detecção , Rios , Solventes , Turquia
19.
Ecotoxicol Environ Saf ; 132: 101-10, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27288953

RESUMO

We report in this study the magnetic properties and partitioning patterns of selected trace metals (Pb, Zn, Cu, Cd, Ni) in roadside and off-road (>200m distance from the road edge) agricultural soils collected along two major highways in Greece. Sequential extractions revealed that the examined trace metals for the entire data set were predominantly found in the residual fraction, averaging 37% for Cd up to 80% for Cu. Due to the strong influence of lithogenic factors, trace metal pseudototal contents of the roadside soils did not differ significantly to those of the off-road soils. Magnetic susceptibility and frequency dependent magnetic susceptibility determinations showed a magnetic enhancement of soils; however, it was primarily related to geogenic factors and not to traffic-derived magnetic particles. These results highlight that in areas characterized by strong geogenic backgrounds, neither pseudototal trace metal contents nor magnetic properties determinations effectively capture traffic-related contamination of topsoils. The vehicular emission signal was traced by the increased acid-soluble and reducible trace metal contents of the roadside soils compared to their off-road counterparts. In the case of Cu and Zn, changes in the partitioning patterns were also observed between the roadside and off-road soils. Environmental risks associated with agricultural lands extending at the margins of the studied highways may arise from the elevated Ni contents (both pseudototal and potentially mobile), and future studies should investigate Ni levels in the edible parts of plants grown on these agricultural soils.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Agricultura , Monitoramento Ambiental , Grécia , Solo/química , Meios de Transporte , Emissões de Veículos
20.
Toxicol Ind Health ; 32(3): 507-16, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24193050

RESUMO

In the present work, 6 honeydew samples of known geographical and botanical origins and 11 honeybee samples were analyzed to detect possible contamination by the thermoelectric power plants in Mugla, Turkey. The contents of trace elements were determined by atomic absorption spectrometry after application of microwave digestion. The samples from the thermal power plants, which were 10-22 km away from the hives, that did not cause pollution in honeydew honeys were also analyzed. The levels of copper, cadmium (Cd), lead (Pb), zinc, manganese, iron, chromium, nickel, and aluminum were similar to the values found in other recent studies in literature. However, it was found that the contamination levels of the toxic elements such as Pb and Cd in honeybee samples measured relatively higher than that of honey samples. The study concludes that honeybees may be better bioindicators of heavy metal pollution than honey.


Assuntos
Abelhas/química , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Mel/análise , Metais Pesados/análise , Centrais Elétricas , Animais , Espectrofotometria Atômica , Turquia
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