Extraction and separation feasibility of cerium (III) and lanthanum (III) from aqueous solution using modified graphite adsorbent.

Graphite (GR) and graphite/alginate (GRA) composite were synthesized utilizing the thermal annealing technique and used as a new adsorbent material for the selective separation and removal of La(III) and Ce(III) from aqueous solutions. Fourier transform infrared (FTIR) spectroscopy, thermal analysis (DTA, TGA), X-ray diffraction (XRD), surface area, porosity, and scanning electron microscope (SEM) were also used to characterize the generated material. Distinct experiments were performed to test the ability of the GRA to La(III) and Ce(III) removal, which include the effect of pH, shaken time, initial concentration of La(III), and Ce(III) at different temperatures range. After 20 min, both ions have reached equilibrium. The pseudo second-order kinetic model was chosen as one which best fits the experimental evidence and better reflects the chemical sorption process. Adsorption isotherm was studied using the Langmuir, Freundlich, and D-R models. The Langmuir model was used to better fit the results obtained. At 25 °C, Ce(III) and La(III) have maximum monolayer capacities of 200 and 83.3 mg/g, respectively. The sorption was endothermic reaction and spontaneous, as illustrated by the data of thermodynamics studies. GRA has the ability to be used as a novel lanthanide adsorbent material, especially for selective separation between Ce(III) and La(III).

Oxidized alginate/gelatin decorated silver nanoparticles as new nanocomposite for dye adsorption.

In the current article di-aldehyde alginate (DAA) crosslinking gelatin (Ge) hydrogel was prepared and investigated for stabilizing silver nanoparticles. DAA/Ge decorated silver nanoparticles hydrogel was characterized by IR, XRD, TGA, SEM and AFM. The outcomes demonstrate that silver nanoparticles with uniform sizes were homogenously distributed through DAA/Ge hydrogel. DAA/Ge decorated silver nanocomposite was examined for the rejection of methylene blue (MB) from aqueous solutions. Comparing with DAA/Ge hydrogel, the nanocomposite has high efficiency for removal of MB. The highest MB removal efficiency was observed at pH 7 and the adsorption process is well described by pseudo-second order and Langmuir adsorption model with adsorption capacity of 625 mg/g. Our results proved that the DAA/Ge/Ag nanocomposite could be used for removal of MB from decontaminated solutions.

All Solid-State Poly (Vinyl Chloride) Membrane Potentiometric Sensor Integrated with Nano-Beads Imprinted Polymers for Sensitive and Rapid Detection of Bispyribac Herbicide as Organic Pollutant.

All-solid-state potentiometric sensors were prepared by using polyaniline (PANI) as the solid contact material. A film of PANI (thickness approximately being 0.25 µm) was deposited on a solid substrate (carbon screen printed platform). The PANI layer was subsequently coated with an ion-selective membrane (ISM) containing uniform-sized molecularly imprinted nanoparticles to produce a solid-contact ion-selective electrode (SC/ISE) for bispyribac herbicide (sensor I). In addition, aliquat 336 was also used as an ion exchanger in plasticized PVC membrane (sensor II). The proposed sensors revealed a remarkably improved sensitivity towards bispyribac ions with anionic slopes of -47.8 ± 1.1 (r² = 0.9995) and -44.4 ± 1.4 (r² = 0.9997) mV/decade over a linear range 1.0 × 10-2⁻8.6 × 10-6 M, 1.0 × 10-2⁻9.0 × 10-6 M and detection limits of 1.33 and 1.81 µg/mL for sensors I and II, respectively.Selectivity of both sensors is significantly high for different common pesticides and inorganic anions. The potential stability of the SC/ISEs was studied using chronopotentiometry. Electrochemical impedance spectrometry was used to understand the charge-transfer mechanisms of the different types of ion-selective electrodes studied. The impedance response of the electrodes was modelled by using equivalent electrical circuits. The sensors were used for a direct measurement of the bispyribac content in commercial herbicide formulations and soil samples collected from agricultural lands planted with rice and sprayed with bispyribac herbicide. The results agree fairly well with data obtained using HPLC method.

Cetirizine dihydrochloride interaction with some diclofenac complexes.

IR, 1H NMR and mass spectrometric studies showed that cetirizine dihydrochloride interacted strongly with diclofenac sodium, even when the latter was metal bound, forming high molecular weight stable adducts. These new formations were unaffected by the possible steric constraints that may exist because of coordination yet did not have the power to break the formed coordinate bonds. The formed ionic bond took place between the carbonyl ion of diclofenac and the positively charged piperazine ring of cetirizine, forming a ternary compound in the case of the divalent metal clusters (Ca{(dic)2.2H2O}, Mg{(dic)2.2H2O}, Zn{(dic)2.2H2O}) and a quaternary one with the trivalent iron cluster (Fe{dic}3.3H2O). IR bands assigned to nuNH, deltaNH and nuC-N were shifted to lower frequency values in the spectra of the complexes; thus showing that coordination took place at the NH of the diphenylamine. TG and elemental analysis confirmed these results.

Drug-drug interaction between diclofenac, cetirizine and ranitidine.

The interactions between diclofenac (1), cetirizine (2) and ranitidine (3) were investigated by thermal analyses and UV, IR and (1)H NMR spectroscopic studies. In aqueous solution interaction occurred only between 1 and 2, yielding a high molecular weight (1:1), water insoluble ionic salt. Weak charge transfer (CT) interaction exists between the doubly charged piperazine moiety in 2, acting as an electron acceptor and (1). This CT interaction originates from the aromatic groups in 1. The CT band observed at approximately 315 nm exhibits very low absorbance as a result of the partial neutralization of the two positive charges present in the ionic salt. The IR bands of the mixture have wave numbers at nu 3323.1, 1695.3, and delta 1321.1-1210 cm(-1) indicating the presence of the NH group and the neutralized carbonyl group of 1, as well as the carboxylic group of 2. The 1,2,3-substitutions in the benzene ring of 1 in the mixture appear at 1161.1 cm(-1). The (1)H NMR of the mixed drugs shows singlet, triplet and multiplet proton signals due to the same effect.