Polymer/Activated Charcoal-Coated Magnetite for the Adsorptive Removal of Emerging Contaminants: Stepwise Synthesis via Two Sequential Routes

Emerging contaminants pose great health risks to humans and living organisms, even when released at minute concentrations over prolonged exposure times. In this work, we fabricate nanocomposites based on activated charcoal-coated magnetite by incorporating the biopolymers of xylan or pectin into their structure. Two synthesis routes which differ in their sequential steps were investigated. It was demonstrated that the synthesis route affects the morphology, textural properties, and chemical structure of the nanocomposites, as confirmed by Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and Fourier Transform Infra-red (FTIR) measurements, respectively. Hence, in turn, it influences the performance of the nanocomposites in their adsorptive removal for the emerging contaminants of Fluoxetine and Famotidine, whose presence in wastewater have been confirmed in several studies

Polymer/Activated Charcoal-Coated Magnetite for the Adsorptive Removal of Emerging Contaminants: Stepwise Synthesis via Two Sequential Routes

Emerging contaminants pose great health risks to humans and living organisms, even when released at minute concentrations over prolonged exposure times. In this work, we fabricate nanocomposites based on activated charcoal-coated magnetite by incorporating the biopolymers of xylan or pectin into their structure. Two synthesis routes which differ in their sequential steps were investigated. It was demonstrated that the synthesis route affects the morphology, textural properties, and chemical structure of the nanocomposites, as confirmed by Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and Fourier Transform Infra-red (FTIR) measurements, respectively. Hence, in turn, it influences the performance of the nanocomposites in their adsorptive removal for the emerging contaminants of Fluoxetine and Famotidine, whose presence in wastewater have been confirmed in several studies

Multifunctional Chitosan/Xylan-Coated Magnetite Nanoparticles for the Simultaneous Adsorption of the Emerging Contaminants Pb(II), Salicylic Acid, and Congo Red Dye

In this work, we develop chitosan/xylan-coated magnetite (CsXM) nanoparticles as eco-friendly efficient adsorbents for the facile removal of contaminants from water. Characterization of CsXM using Fourier Transform Infra-Red (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), Zeta potential measurements, and Brunauer-Emmet-Teller (BET) analysis, confirmed the successful preparation of a chitosan/xylan complex coated over magnetite, which is characterized by being mesoporous, thermally stable and of neutral charge. Three contaminants, Pb(II), salicylic acid (SA), and congo red (CR), were chosen as representative pollutants from three major classes of contaminants of emerging concern: heavy metals, pharmaceuticals, and azo dyes. Pb(II), SA, and CR at initial concentrations of 50 ppm were removed by 64.49, 62.90, and 70.35%, respectively, on applying 6 g/L of CsXM. The contaminants were successfully removed in ternary systems, with Pb (II) and SA being more competitive in their adsorption than CR. Adsorption followed the Freundlich isotherm model and the pseudo-second order kinetic model, while the binding was suggested to occur mainly via chemical chelation for Pb(II) and physical interaction for SA and CR, which demonstrates the multifunctional potential of the nanoparticles to capture different contaminants regardless of their charge

Ion Selective Membrane Electrodes for the Determination of Xylometazoline Hydrochloride in Rabbit Aqueous Humor using 2-Hydroxy Propyl -cyclodextrin and Calix[6]arene as Ionophores Analytical & Bioanalytical Electrochemistry

Abstract-Three novel Xylometazoline Hydrochloride (XYLO) selective electrodes were investigated with Dioctyl phthalate (DOP) as a plasticizer in a polymeric matrix of polyvinyl chloride (PVC). Sensor 1 was fabricated using Phosphomolybdic acid (PMA) as an anionic exchanger without incorporation of an ionophore. Sensor 2 used 2-hydroxy propyl -cyclodextrin (hp-CD) as an ionophore while sensor 3 was constructed using calix were obtained using sensors 1, 2 and 3, respectively. Nernstian slopes of 49.78, 56.21 and 46.20 mV/decade over the pH range of 5-9 for sensors 1, 2 and 5-7 for sensor 3 were observed. The selectivity coefficients of the developed sensors indicated excellent selectivity for XYLO. The utility of 2-hydroxy propyl -cyclodextrin and cali

Computer-aided design of magnetic molecularly imprinted polymer nanoparticles for solid-phase extraction and determination of levetiracetam in human plasma

Analytical methods should be accurate and specific to measure plasma drug concentration. Nevertheless, current sample preparation techniques suffer from limitations, including matrix interference and intensive sample preparation. In this study, a novel technique was proposed for the synthesis of a molecularly imprinted polymer (MIP) on magnetic Fe(3)O(4) nanoparticles (NPs) with uniform core–shell structure. The Fe(3)O(4)@MIPs NPs were then applied to separate and enrich an antiepileptic drug, levetiracetam, from human plasma. A computational approach was developed to screen the functional monomers and polymerization solvents to provide a suitable design for the synthesized MIP. Different analysis techniques and re-binding experiments were performed to characterize the Fe(3)O(4)@MIP NPs, as well as to identify optimal conditions for the extraction process. Adsorption isotherms were best fitted to the Langmuir model and adsorption kinetics were modeled with pseudo-second-order kinetics. The Fe(3)O(4)@MIP NPs showed reasonable adsorption capacity and improved imprinting efficiency. A validated colorimetric assay was introduced as a comparable method to a validated HPLC assay for the quantitation of levetiracetam in plasma in the range of 10–80 μg mL(−1) after extraction. The results from the HPLC and colorimetric assays showed good precision (between 1.08% and 9.87%) and recoveries (between 94% and 106%) using the Fe(3)O(4)@MIP NPs. The limit of detection and limit of quantification were estimated to be 2.58 μg mL(−1) and 7.81 μg mL(−1), respectively for HPLC assay and 2.32 μg mL(−1) and 7.02 μg mL(−1), respectively for colorimetric assay. It is believed that synthesized Fe(3)O(4)@MIP NPs as a sample clean-up technique combined with the proposed assays can be used for determination of levetiracetam in plasma

Adsorptive Removal of Fluoroquinolones from Water by Pectin-Functionalized Magnetic Nanoparticles: Process Optimization Using a Spectrofluorimetric Assay

The efficiency of adsorption of two photosensitive fluoroquinolones; Ciprofloxacin (CIP) and Moxifloxacin (MOX), on the surface of synthesized magnetite/pectin nanoparticles (MPNPs) and magnetite/silica/pectin nanoparticles (MSPNPs) was studied from aqueous solution under varying experimental conditions. A validated spectrofluorimetric assay was developed for monitoring of CIP and MOX intact drugs and their photodegraded molecules concentrations. To optimize the working conditions which influence the drugs sorption, a 2⁴ full factorial experimental design was implemented. The maximum percentage of removal was attained as 89% (type of sorbent = MSPNPs, pH = 7.0, initial drug concentration = 5 mg/L, and contact time = 30 min). The studied factorspH, NPs loading, initial drug concentration, and contact timewere significant for both types of sorbents. The most significant variable was pH, and the highest CIP and MOX adsorption occurred at pH = 7.0. Equilibrium isotherm data were fitted to Langmuir, Freundlich, and Sips equations, and the Sips model showed the best fit with equilibrium isotherm data. Furthermore, pseudo-first- and pseudo-second-order kinetic models were used to analyze sorption kinetics, and it was found that adsorption of the investigated fluoroquinolones followed pseudo-second-order kinetics. We believe that our synthesized NPs can be used as effective adsorbents for fluoroquinolones and their photodegraded molecules removal from aqueous solutions