Preparation and characterization of Zn(II) ion-imprinted polymer based on salicylic acrylate for recovery of Zn(II) ions

Ion-Imprinted Polymeric Materials for Selective Adsorption of Heavy Metal Ions from Aqueous Solution

The introduction of selective recognition sites toward certain heavy metal ions (HMIs) is a great challenge, which has a major role when the separation of species with similar physicochemical features is considered. In this context, ion-imprinted polymers (IIPs) developed based on the principle of molecular imprinting methodology, have emerged as an innovative solution. Recent advances in IIPs have shown that they exhibit higher selectivity coefficients than non-imprinted ones, which could support a large range of environmental applications starting from extraction and monitoring of HMIs to their detection and quantification. This review will emphasize the application of IIPs for selective removal of transition metal ions (including HMIs, precious metal ions, radionuclides, and rare earth metal ions) from aqueous solution by critically analyzing the most relevant literature studies from the last decade. In the first part of this review, the chemical components of IIPs, the main ion-imprinting technologies as well as the characterization methods used to evaluate the binding properties are briefly presented. In the second part, synthesis parameters, adsorption performance, and a descriptive analysis of solid phase extraction of heavy metal ions by various IIPs are provided.

Simultaneous Functionalization and Reduction of Magnetic Graphene Oxide by L-Histidine and its Application for Magnetic Separation/Preconcentration of Antioxidant Trace Elements

In the present study, for the first time, the magnetic graphene oxide was simultaneously functionalized and reduced with the aim of imidazole-based L-histidine amino acid (rGO/Fe₃O₄-histidine). The prepared nanocomposite was characterized by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy, and vibrating sample magnetometer. The synthesized rGO/Fe₃O₄-histidine nanosheets were implied for solid phase extraction of ultra-trace amounts of Zn²⁺, Cu²⁺_, and Mn²⁺ from biological samples prior to ICP-OES determination. The calibration curves were linear in the concentration ranges of 0.4-182.0, 0.4-215.0, and 0.2-168.5 μg L^-1 for Zn²⁺, Cu²⁺, and Mn²⁺, respectively. The limits of detection were 0.12, 0.10, and 0.04 μg L^-1 for Zn²⁺, Cu²⁺, and Mn²⁺, respectively. The relative standard deviations (RSDs) at 50.0 μg L^-1 for single-sorbent repeatability and sorbent-to-sorbent reproducibility were less than 6.7 and 9.2% (n = 5), respectively. The accuracy of the method was confirmed by the analysis of a serum quality control material (QCM, Seronorm™ Human Serum REF NO 203105) and hair certified reference material (CRM, Human Hair IAEA-086).

Determination of optimal adsorption-desorption conditions for selective removal of Ni(II) from petrochemical samples using ion imprinted nanosorbent

Nanoporous particles Ni(II) ion imprinted polymer (IIP), and non-imprinted polymer (NIP) in the absence of Ni(II) ion, with 18-70 nm dimensions were synthesized, and characterized by Fourier transform infrared, energy dispersive X-ray and nuclear magnetic resonance spectroscopic methods. Then, the surface area, pore size and structural composition of the products were characterized by Brunauer-Emmett-Teller and scanning electron microscope methods. Then, modified electrodes by the IIP for Ni(II) sensing and determination, were constructed and their catalytic activity were investigated by cyclic voltammetric method. Some parameters like desorption solvent, amount of sorbent, pH and contact time were optimized, and the measurements were all conducted under optimal conditions. The optimum pH for maximum sorption was obtained 7.8. In the optimum conditions, the maximum sorbent capacity of the IIP was obtained 371.9 µM/g. The limit of detection and relative standard deviation (n = 5) were obtained 1.3 ng/mLand 1.47%, respectively. The pre-concentration procedure revealed a linear curve within the concentration range of 10-6000 ng/mL and a good linearity with squared correlation coefficient of r2 0.9991 was achieved. The method was applied successfully for determination of Ni(II) ion in petrochemical samples.

Development of flow injection analysis-solid phase extraction based on ion imprinted polymeric nanoparticles as an efficient and selective technique for preconcentration of zinc ions from aqueous solution

Here, a new flow injection analysis-solid phase extraction (FIA-SPE) technique was developed by using zinc ion imprinted polymeric nanoparticles (Zn-IIP NPs) for the separation and preconcentration of Zn²⁺ions from aqueous solutions.