Preparation of polysulfone hollow fiber affinity membrane modified with mercapto and its recovery properties. II. Preparation of PSF‐SH hollow fiber affinity membrane for recovery of Hg2+

A high qualified polysulfone hollow fiber affinity membrane modified with mercapto as chelating groups was prepared by phase inversion technology using chlormethyl polysulfone (CMPSF) as membrane matrix materials, through the reaction between thiourea and CMPSF hollow fiber matrix membrane to afford the methyl isothiourium polysulfone and was then alkaline hydrolyzed. The adsorption isotherms of the hollow fiber affinity membrane chromatography for Hg²⁺ were determined, and the effects of mobile phase conditions and the operating parameters on removal performance of the hollow fiber affinity membrane chromatography for Hg²⁺ were also investigated. The experimental results showed that adsorption isotherms of Hg²⁺ could be described by the Langmuir isotherm. Addition of NaCl into feed solution for the increase of ionic strength was harmful for the removal of Hg²⁺. The recovery of Hg²⁺ decreased at low pH and the optimum range of pH was from 5.0 to 7.0. The feed concentration had a remote effect on recovery of Hg²⁺ at the specified loading amount of Hg²⁺, and the Hg²⁺ could be removed from different concentration feed solution by the hollow fiber affinity membrane chromatography. The increase of feed flow rate led to slight decrease of recovery of Hg²⁺ at the specified loading amount of Hg²⁺. The hollow fiber affinity membrane chromatography could be operated at height feed flow rate and a large scale removal of Hg²⁺ could be realized. With the increase of load amount, Hg²⁺ recovery decreased, but the saturation degree of hollow fiber affinity membrane chromatography increased. According to required recovery of Hg²⁺ and the saturation degree of membrane chromatography, the optimum loading amount of Hg²⁺ should be selected in the actual removal of Hg²⁺. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4795–4803, 2006     

Preparation of a heterogeneous hollow‐fiber affinity membrane having a mercapto chelating resin and its recovery of Hg2+ cations

A kind of heterogeneous hollow‐fiber affinity filter membrane with a high chelating capacity for Hg²⁺ was prepared by phase separation with blends of a mercapto chelating resin and polysulfone as the membrane materials, N,N‐dimethylacetamide as the solvent, and water as the extraction solvent. The adsorption isotherms of the hollow‐fiber affinity filter membrane for Hg²⁺ were determined. The heterogeneous hollow‐fiber affinity filter membrane was used for the adsorption of Hg²⁺ cations through the coordination of the mercapto group and Hg²⁺ cations, and the effects of the morphology and structure of the affinity membrane on the chelating properties were investigated. The chelating conditions, including the chelating resin grain size, pH value, concentration of the metallic ion solution, mobile phase conditions, and operating parameters, had significant effects on the chelating capacity of the hollow‐fiber affinity filter membrane. The results revealed that the greatest chelating capacity of the hollow‐fiber affinity filter membrane for Hg²⁺ was 1090 μg/cm² of membrane under appropriate conditions, and the adsorption isotherms of Hg²⁺ could be described by the Langmuir isotherm. The dynamic chelating experiments indicated that the hollow‐fiber affinity membrane could be operated at a high feed flow rate and that large‐scale removal of Hg²⁺ could be realized. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thiacalixarenes with Sulfur Functionalities at Lower Rim: Heavy Metal Ion Binding in Solution and 2D-Confined Space

Sulfur-containing groups preorganized on macrocyclic scaffolds are well suited for liquid-phase complexation of soft metal ions; however, their binding potential was not extensively studied at the air–water interface, and the effect of thioether topology on metal ion binding mechanisms under various conditions was not considered. Herein, we report the interface receptor characteristics of topologically varied thiacalixarene thioethers (linear bis-(methylthio)ethoxy derivative L², O₂S₂-thiacrown-ether L³, and O₂S₂-bridged thiacalixtube L⁴). The study was conducted in bulk liquid phase and Langmuir monolayers. For all compounds, the highest liquid-phase extraction selectivity was revealed for Ag⁺ and Hg²⁺ ions vs. other soft metal ions. In thioether L² and thiacalixtube L⁴, metal ion binding was evidenced by a blue shift of the band at 303 nm (for Ag⁺ species) and the appearance of ligand-to-metal charge transfer bands at 330–340 nm (for Hg²⁺ species). Theoretical calculations for thioether L² and its Ag and Hg complexes are consistent with experimental data of UV/Vis, nuclear magnetic resonance (NMR) spectroscopy, and single-crystal X-ray diffractometry of Ag–thioether L² complexes and Hg–thiacalixtube L⁴ complex for the case of coordination around the metal center involving two alkyl sulfide groups (Hg²⁺) or sulfur atoms on the lower rim and bridging unit (Ag⁺). In thiacrown L³, Ag and Hg binding by alkyl sulfide groups was suggested from changes in NMR spectra upon the addition of corresponding salts. In spite of the low ability of the thioethers to form stable Langmuir monolayers on deionized water, one might argue that the monolayers significantly expand in the presence of Hg salts in the water subphase. Hg²⁺ ion uptake by the Langmuir–Blodgett (LB) films of ligand L³ was proved by X-ray photoelectron spectroscopy (XPS). Together, these results demonstrate the potential of sulfide groups on the calixarene platform as receptor unit towards Hg²⁺ ions, which could be useful in the development of Hg²⁺-selective water purification systems or thin-film sensor devices.     

Priority pollutants (Hg and Cd) removal from water by ETS-4 titanosilicate

The synthetic microporous titanosilicate material ETS-4 has been used for the removal of Hg²⁺ and Cd²⁺ from water. Batch stirred experiments were carried out to study the equilibrium and the kinetics of the removal of Hg²⁺ and Cd²⁺ from water. It has been demonstrated that ETS-4 has a great affinity for both these metal cations even when their initial concentrations are low. The uptake rates for both Hg²⁺ and Cd²⁺ were well described by the pseudo-second order model which constants confirmed that the kinetics of the removal of Cd²⁺ is faster than that of Hg²⁺. However, at the equilibrium, ETS-4 has a higher capacity to remove Hg²⁺ than Cd²⁺. Adsorption isotherms for both Hg²⁺ and Cd²⁺ were well fitted to Langmuir isotherm and the corresponding monolayer capacities of ETS-4 are 0.43 and 0.24 µmol mg^- 1, respectively, which are quite consistent with those predicted by the pseudo-second order kinetic equation. Hence, the contribution of this work is to support the use of this material for the removal of Hg²⁺ and Cd²⁺ from water.     

Synthesis,characterization, and properties for Hg2+ of new chelating resin containing sulfoxide and 3‐aminopyridine

A new chelating resin (PVESO‐AP) containing sulfoxide and 3‐aminopyridine (AP) was synthesized by using chloromethylated polystyrene‐co‐divinylbenzene (PS‐Cl) as material. Its structure was characterized by infrared spectra and elemental analysis. The adsorption capacities of the newly formed resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, Cd²⁺, and Ni²⁺ were determined at pH 2 and 5. In addition, the adsorption selective coefficients for Hg²⁺ in several binary mixture systems were investigated by batch experiment method. The results showed that this resin had high adsorption selectivity for Hg²⁺. The adsorption kinetics and isothermal of PVESO‐AP for Hg²⁺ at different temperatures were also investigated. The adsorption kinetics showed that the apparent activation energy E_a was 13.71 kJ/mol. The results also showed that the Langmuir model was better than the Frundlich model to describe the isothermal process of PVESO‐AP resin for Hg²⁺. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Selective Biosorption of Zirconium and Hafnium from Acidic Aqueous Solutions by Rice Bran,Wheat Bran and Platanus Orientalis Tree Leaves

Abstract

The Zr(IV) and Hf(IV) biosorption characteristics of rice bran, wheat bran and Platanus orientalis tree leaves were examined as a function of initial pH, contact time, temperature, and initial metal ions concentration. Adsorption equilibriums were achieved in about 1, 5 and 40 min for rice bran, wheat bran, and leaves respectively. The biosorption behavior of leaves was significantly affected by solution pH whereas rice bran and wheat bran adsorption efficiencies were slightly affected by solution pH. The Freundlich and Langmuir adsorption equations, which are commonly used to describe sorption equilibrium for metals removal by biomasses, were use to represent the experimental and equilibrium data fitted well to the Langmuir isotherm model. The negative Gibbs free energy values obtained in this study with rice bran wheat bran and Platanus orientalis tree leaves confirmed the feasibility of the process and the spontaneous nature of sorption. In the optimum conditions, the adsorption efficiencies of other metal ions such as Fe³⁺, Cu²⁺, Pb²⁺, Hg²⁺, La³⁺, Ce³⁺ were significantly lower than Zr(IV) and Hf(IV) ions and these biomasses are excellent sorbents for the selective uptake of proposed ions from acidic aqueous solutions.     

Removal of Hg2+ from aqueous solution using a novel composite carbon adsorbent

A novel composite carbon adsorbent (GCA) has been prepared by immobilizing activated carbon and genipin‐crosslinked chitosan into calcium alginate gel beads via entrapment and applied to the removal of mercury (Hg²⁺) ions from aqueous solution (e.g., drinking water). Two bead sizes and two mixing ratios of components were obtained and characterized. Batch experiments were performed to study the uptake equilibrium and kinetics of Hg²⁺ ions by the GCA. The Hg²⁺ adsorption capacity of GCA was found to be dependent of pH and independent of size of the adsorbent. The Hg²⁺ adsorption rate of GCA increases with decreasing its bead size. However, both adsorption capacity and rate of GCA for Hg²⁺ increase with increasing its chitosan content. Otherwise, it was shown that the GCA has higher Hg²⁺ adsorption capacity and rate than activated carbon, which might be caused by the incorporation of chitosan into the GCA. The maximum Hg²⁺ adsorption capacity of GCA was found to be 576 mg/g, which is over seven times higher than that of activated carbon. Our results reveal the uniform distribution of activated carbon and chitosan within the alginate gel bead and that Hg²⁺ ions can diffuse inside the bead. It also demonstrated the feasibility of using this GCA for Hg²⁺ removal at low pH values. The Hg²⁺ absorbed beads of the GCA can be effectively regenerated and reused using H₂SO₄. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

ION EXCHANGE PROPERTIES OF THE SULFUR-MODIFIED BIOTITE

ABSTRACT

The ion exchange behavior of a sulfur-modified biotite towards Pb²⁺, Hg²⁺, Co²⁺, Cu²⁺, Cd²⁺ and Zn²⁺ ions has been studied. The ion exchange isotherms of divalent cations were determined and concentration equilibrium constants as a function of metal loading were analyzed. Sulfur modified biotite exhibits high affinity for Hg²⁺, Pb²⁺, Cu²⁺ and Cd²⁺ ions in individual solutions and in the presence of electrolytes. About 200 mg Hg/g uptake in 1·10^?3 M Hg²⁺ solution and ～ 35 mg Hg/g in groundwater simulant or an alkaline simulant 2 M in NaN0₃ + 1 M in NaOH was found. The possibility of a complex ion exchange and precipitation mechanism of the sulfur modified biotite towards the soft cations is proposed.     

Elimination of inorganic mercury from waste waters using crandallite‐type compounds

The removal of inorganic mercury from waste water streams arising from mines, using an artificial amorphous compound of the crandallite type synthesized in our laboratory, Ca_0.5Sr_0.5Al₃(OH)₆(HPO₄) (PO₄), has been investigated. This compound exhibits an extremely wide range of ionic substitutions: Ca²⁺ and Sr²⁺ were interchanged with Hg²⁺, so the mercury content of the waste water, ranging from 70 to 90 ppm, was reduced to less than 0.1 ppm. The process has been studied under batch conditions. The crandallite showed a high capacity for the exchange of mercury from mercuric nitrate solutions, 1.555 meq g^?1. The ion‐exchange equilibrium isotherms for Hg²⁺ were correlated by the Langmuir equation. The recovery of mercury from Hg‐crandallite using HCl solutions and thermal treatment was also studied. Optimum recuperation of mercury is achieved by chemical reaction with HCl solution (pH 2.25). At these conditions, 75% of the mercury is recovered as the HgCl₄^2? complex in a simple batch process, and the crandallite (in the protonic form) can be reused. © 2003 Society of Chemical Industry     

Adsorption kinetics and equilibrium of copper from ethanol fuel on silica-gel functionalized with amino-terminated dendrimer-like polyamidoamine polymers

The adsorption kinetics and equilibrium of silica-gel functionalized with amino-terminated dendrimer-like polyamidoamine (PAMAM) polymers SiO₂-G1.0, SiO₂-G2.0 and SiO₂-G3.0 for Cu²⁺ in ethanol fuel were investigated by using batch method. The results indicated that the all the adsorptions of the three adsorbents followed well the pseudo second-order model. The adsorption isotherms were fitted by Langmuir model, Freundlich model and Dubinin–Radushkevich (D–R) model. The results showed that Langmuir model was more suitable to describe the equilibrium data than the Freundlich model. From the D–R isotherm model, the mean free energy E calculated of the three adsorbents showed that the adsorptions were taken place by physical processes. Thermodynamic parameters, ΔG⁰, ΔH⁰ and ΔS⁰ indicated the Cu²⁺ adsorption to be endothermic and spontaneous with decreased randomness at the solid-solution interface, resulting in their higher adsorption capacities at higher temperature. The effect of generation number of PAMAM polymers loaded on silica-gel, contact time, initial concentration and temperatures on the adsorption capabilities were studied in detail. Moreover, the adsorption mechanism of copper from ethanol fuel was also presumed.     

Development of fly ash and iron ore tailing based porous geopolymer for removal of Cu(II) from wastewater

This work aims to verify the feasibility of utilizing iron ore tailing (IOT) in porous geopolymer and intends to broaden the application of porous geopolymer in heavy metal removal aspect. Porous geopolymer was prepared using fly ash as resource material, which was partially replaced by IOT at level of 30%, by weight, with H₂O₂ as foaming agent and removal efficiency, adsorption affecting factors, adsorption isotherms and thermodynamics of Cu²⁺ by the developed porous geopolymer were investigated.The experimental results uncover that the porous amorphous geopolymer was successful synthesized with total porosity of 74.6%. The transformation of fly ash and IOT into foaming geopolymer leads to the formation of porous structure encouraging Cu²⁺ sorption. Batch sorption tests were carried out and geopolymer dosage, Cu²⁺ initial concentration, pH, contact time and temperature were the main concern. Both Langmuir and Freundlich models could explain the adsorption of Cu²⁺ on the porous geopolymer due to the high fitting coefficients. The uptake capacity reaches the highest value of 113.41 mg/g at 40 °C with pH value of 6.0. The thermodynamic parameters ΔHº, ΔSº and ΔGº suggests the spontaneous nature of Cu²⁺ adsorption on porous geopolymer and the endothermic behavior of sorption process.     

Enhanced Hg2+ removal and Hg0 re-emission control from wet fuel gas desulfurization liquors with additives

Secondary atmospheric pollutions may result from wet flue gas desulfurization (FGD) systems caused by the reduction of Hg²⁺ to Hg⁰. The present study employed three agents: Na₂S, 2,4,6-trimercaptotiazine, trisodium salt nonahydrate (TMT) and sodium dithiocarbamate (DTCR) to precipitate aqueous Hg²⁺ in simulated desulfurization solutions. The effects of the precipitator’s dosing quantity, the initial pH value, the reaction temperature, the concentrations of Cl^? and other metal ions (e.g. Cu²⁺ and Pb²⁺) on Hg²⁺ removal were studied. A linear relationship was observed between Hg²⁺ removal efficiency and the increasing precipitator’s doses along with initial pH. The addition of chloride and metal ions impaired the Hg²⁺ removal from solutions due to the complexation of Cl^? and Hg²⁺ as well as the chelating competition between Hg²⁺ and other metal ions. Based on a comprehensive comparison of the treatment effects, DTCR was found to be the most effective precipitating agent. Moreover, all the precipitating agents were potent enough to inhibit Hg²⁺ reduction as well as Hg⁰ re-emission from FGD liquors. More than 90% Hg²⁺ was captured by precipitating agents while Hg²⁺ reduction efficiency decreased from 54% to just less than 3%. The additives could efficiently control the secondary Hg⁰ pollution from FGD liquors.     

The Extraction Ability and Sensitivity of Porphyrazine Derivatives Towards Some Transition Metal Cations

The synthesis of novel metal-free and magnesium porphyrazines, peripherally substituted with dithia-dioxa (S₂O₂) and tetrathia (S₄) 14-membered macrocycles were performed by cyclotetramerization of (6Z)-1,3,4,9,10,12-hexahydro-2,5,8,11-benzo-dioxadithiacyclotetradecine-6,7-dicarbodinitrile (3) or (6Z)-1,3,4,9,10,12-hexahydro 2,5,8,11-benzotetrathiacyclotetradecine-6,7-dicarbodinitrile (5). The metal-free porphyrazines have been obtained by known route. The structure of compounds were characterized by elemental analysis and ¹H, ¹³C NMR, IR, UV-vis, and MS spectral data. The solvent extraction properties of the synthesized compounds towards some metal cations, such as Ag(I), Hg(II), Cu(II), Mn(II), Cr(III), Ni(II), Pb(II), and Zn(II) have been investigated. The effect of Cu²⁺, Mn²⁺, Ni²⁺, Pb²⁺, Sr²⁺, Al³⁺, Zn²⁺, Ba²⁺, Cd²⁺, Co²⁺, Hg²⁺, and Ag⁺ ions on the absorption spectra of the compounds were investigated by means of spectrophotometric method. Magnesium porphyrazine with S₂O₂ (6) interacted within Hg²⁺ ion specifically of all the tested metal ions.     

Adsorption of Hg2+ on a novel chelating fiber prepared by preirradiation grafting and amination

A novel chelating fiber was prepared by the irradiation‐induced grafting copolymerization of glycidyl methacrylate on polypropylene fiber and consequent amination with diethylenetriamine. The effects of the reaction conditions, such as reaction time, temperature, and monomer concentration, on the degree of grafting were investigated. The optimal conditions for grafting were found to be 3 h, 100°C, and a 50% (v/v) glycidyl methacrylate concentration in tetrahydrofuran solution. This fiber showed good adsorption performance at different concentrations of Hg²⁺, in particular for trace Hg²⁺. Under the adsorption conditions of pH = 4, initial concentration = 1000 mg/L, and time = 20 h, the adsorption capacity of the chelating fiber for Hg²⁺ reached 785.28 mg/g. It completely adsorbed the Hg²⁺ ions in solution within a short contact time, showing a very high adsorption rate for Hg²⁺. Furthermore, the chelating fiber also had a high selectivity for mercury, whereas Cu²⁺ coexisted in different concentrations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

CrO4 2− Ions Adsorption by Fe-Modified Pozzolane

Abstract

A Fe-modified pozzolane was prepared and employed for the removal of CrO₄ ^2? ions from aqueous solution under batch type experiments as a function of contact time, initial concentration of metal ion and temperature. The adsorption isotherms are described by means of Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) models. The pozzolane was characterized by XRD diffraction analysis. The results showed that the maximum adsorption capacity of Fe-modified pozzolane for CrO₄ ^2? ions was (3.23 ± 0.01)×10^?3 mmol g^?1. The adsorption was found to be initial concentration and temperature dependent. The thermodynamic parameters values such as ΔH⁰, ΔG⁰, and ΔS⁰ were obtained to predict the nature of adsorption. These values show that the adsorption reaction is endothermic and spontaneous. The results show that the Fe-modified pozzolane, that is an easily available material, can be successfully used as adsorbent of anionic species, such as CrO₄ ^2? ions in aqueous solutions, and can be an alternative for more costly adsorbents used for chromates removal in wastewater treatment processes.     

Poly(benzoxazine‐co‐sulfur): An efficient sorbent for mercury removal from aqueous solution

A novel sulfur‐rich adsorbent, poly(BA‐ala‐co ‐sulfur), was synthesized by reacting allyl functional benzoxazine (BA‐ala) and elemental sulfur. Simultaneous inverse vulcanization and ring‐opening reactions of benzoxazine generated copolymers in several feed ratios. The adsorption behavior of these copolymers was investigated in aqueous solutions containing Hg²⁺. A three level Box–Behnken design with four factors was applied in order to examine the interactive effect of Hg²⁺ concentration (ppm), S % in adsorbent, temperature, and pH. The optimum adsorption conditions were determined as: 10.33 ppm Hg²⁺, 68% S content, 329 K, and pH 6.3. Common isotherm and kinetic models were applied to the experimental data, where the Langmuir isotherm provided the better fit (q _max = 79.36 mg g^?1) and the pseudo‐second order fit indicated chemisorption as the process‐controlling step. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45306.     

Sorption Potential of Styrene‐Divinylbenzene Copolymer Beads for the Decontamination of Lead from Aqueous Media

Abstract

The decontamination of lead ions from aqueous media has been investigated using styrene‐divinylbenzene copolymer beads (St‐DVB) as an adsorbent. Various physico‐chemical parameters such as selection of appropriate electrolyte, contact time, amount of adsorbent, concentration of adsorbate, effect of foreign ions, and temperature were optimized to simulate the best conditions which can be used to decontaminate lead from aqueous media using St‐DVB beads as an adsorbent. The atomic absorption spectrometric technique was used to determine the distribution of lead. Maximum adsorption was observed at 0.001 mol L^?1 acid solutions (HNO₃, HCl, H₂SO₄ and HClO₄) using 0.2 g of adsorbent for 4.83×10^?5 mol L^?1 lead concentration in two minutes equilibration time. The adsorption data followed the Freundlich, Langmuir, and Dubinin‐Radushkevich (D‐R) isotherms over the lead concentration range of 1.207×10^?3 to 2.413×10^?2 mol L^?1. The characteristic Freundlich constants i.e. 1/n=0.164±0.012 and A=2.345×10^?3±4.480×10^?5 mol g^?1 have been computed for the sorption system. Langmuir isotherm gave a saturated capacity of 0.971±0.011 mmol g^?1, which suggests monolayer coverage of the surface. The sorption mean free energy from D‐R isotherm was found to be 18.26±0.75 kJ mol^?1 indicating chemisorption involving chemical bonding for the adsorption process. The uptake of lead increases with the rise in temperature. Thermodynamic parameters i.e. ΔG, ΔH, and ΔS have also been calculated for the system. The sorption process was found to be exothermic. The developed procedure was successfully applied for the removal of lead ions from real battery wastewater samples.     

Synthesis and Metal‐ion Binding Properties of New N2S4O2‐ and N2S5O2‐Donor Macrocycles

Abstract

Synthetic procedures for new mixed‐donor macrocycle compounds were reported. The macrocyclic compounds were used in solvent extraction metal picrates such as Ag⁺, Hg²⁺, Cd²⁺, Zn²⁺, Cu²⁺, Ni²⁺, Mn²⁺, Pb²⁺, and Co²⁺. The metal picrate extractions were investigated at 25±0.1°C with the aid of UV‐visible spectrometry. It was found that 6,7,9,10,12,13,23,24‐octahydro‐19H,26Hdibenzo[h,t](1,4,7,13,16,22,10,19) dioxatetrathiadiazasiclotetracosine‐20,27(21H,28H)‐dione showed selectivity towards Ag⁺, Hg²⁺, and Cd²⁺ among the other metals. The extraction constants (Log K_ex) and complex compositions were determined for the Ag⁺ and Hg²⁺ complexes for this compound and 9,10,12,13,23,24,26,27,29,30‐decahydro‐5H,15H‐dibenzo‐[h,w][1,4,7,13,16,19,25‐,10,22] dioxapentathiadiazacycloheptacosine‐6,16(7H,17H)‐dione.     

Application of selective solid-phase extraction using a new core-shell-shell magnetic ion-imprinted polymer for the analysis of ultra-trace mercury in serum of gallstone patients

ABSTRACT

A new ultrasonically assisted spectrophotometric method was developed using stabilized ion polymer on a modified nano-absorbent as a core- shell-shell absorbent (Fe₃O₄@SiO₂@TiO₂–IIP). It has the advantages of further stabilizing the polymer and consequently and much higher efficiency than its conventional adsorbents. The prepared sorbent was characterized and Its parameters were investigated by a Box–Behnken design. The linear dynamic range and limit of detection were 0.20–28.00 µg L^?1 and 0.05 µg L^?1 respectively. In selectivity study, it was founded that imprinting causes increased affinity of the prepared IIP toward Hg²⁺ ion. The proposed IIP is considered to be promising and selective sorbent for solid-phase extraction and preconcentration of Hg²⁺ ion in sera of different types of gallstone patients.     

The Synthesis of New N2S2‐Macrocyclic Schiff Base Ligands and Investigation of Their Ion Extraction Capability from Aqueous Media

Abstract

Two new macrocyclic Schiff bases, (5) and (7), containing nitrogen‐sulfur donor atoms were designed and synthesized by reaction of α,α′ bis(o‐aminophenylthio)‐1,2‐xylene with glyoxal and phthaldialdehyde, respectively. The liquid‐liquid extraction of metal picrates such as Ag⁺, Hg²⁺, Cd²⁺, Zn²⁺, Cu²⁺, Ni²⁺, Mn²⁺, K⁺, and Na⁺ from aqueous phase to the organic phase was carried out using the novel ligands. The effect of chloroform and dichloromethane as organic solvents over the metal picrate extractions was investigated at 25±0.1°C by using UV‐visible spectrometry. The extractability and selectivity of the tested metal picrates were evaluated. The values of the extraction constants (log K_ex) were determined for the extracted complexes.