Metal Ion Binding Capacity Research Articles

Physicochemical Properties and Metal Ion-Binding Capacity of Thermal-Induced Antarctic Krill Protein Aggregates under Different pH Conditions.

Protein properties can be modified by thermal treatment at different pH values, resulting in the formation of protein aggregates with diverse morphologies and functionalities. This study investigated the morphology of aggregates of Antarctic krill protein (AKPS) formed by thermal treatment (90 °C, 15 min) at pH 2, 3, 4, and 6-12, characterized the different morphologies of AKPS, and determined the metal ion (Ca2+, Fe2+, and Zn2+)-binding capacities. Results showed that heat treatment with different pH values generated various AKPS with distinct morphology and metal ion-binding abilities. AKPS have formed fibrils at pH ≤ 3, particles at pH 4-7, and amorphous aggregates at pH ≥ 8. Fibrous AKPS (pH 2) exhibited a high solubility (80.36%) and strong reducing effect on iron. The binding capacities of Ca2+ and Fe2+ reached 36.08% and 66.75%. Particulate AKPS (pH 6 and 7) primarily only showed Zn2+-binding capacity similar to that of casein phosphopeptide (17.33%). Amorphous AKPS (pH 9-11) displayed the optimal capacity to bind Zn2+ and Fe2+ (26.90% and 74.94%). The alterations in morphology and functional characteristics of AKPS permit the design of various nanostructures for food-derived mineral supplements, thus developing their potential for application in functional foods.

Porous Silicon Nanoparticles Conjugated Magnetite‐Chitosan Graphene Oxide Nanoparticles for Effective Removal of Complex Pollutants

AbstractThe effective removal of complex pollutants is extremely challenging for environmental and material science, especially pollutants including detergents and pesticides do not decompose or degrade in the aquatic environment which cannot be easily removed. Here, a novel biocompatible superparamagnetic nanocomposite integrating the advantages of porous silicon nanoparticles is developed, the chelation ability of chitosan, and graphene‐oxide‐iron that can simultaneously adsorb complex hydrophobic and hydrophilic pollutants on their internal and external surfaces which have significantly improved pollutant removal efficiency over the current existing methods. A porous silicon nanoparticle (PSi) conjugated magnetite‐chitosan‐reduced graphene oxide (MCRGO) nanoparticles (PSi‐MCRGO) are synthesized for complete removal of detergent, pesticide, and toxic heavy metals cadmium and lead ions from water at a favorable room temperature. The adsorption behavior of the nanocomposites fits well with the Freundlich isotherm and pseudo‐second‐order kinetics model by adsorption mechanism. Moreover, the fresh and recycled nanocomposites are easily separated by an external magnetic field for reusability due to super magnetite response and show high binding capacity for toxic heavy metal ions. Furthermore, the nanocomposites are biocompatible and reusable, and for the fourth time, recycled nanocomposites can completely remove toxic heavy metals. Overall, the novel nanocomposites completely remove complex pollutants which hold great potential for real water treatment.

Synthesis, characterization and evaluation of novel HIPE hydrogels: Application for treatment of hazardous waste incineration plant effluent

Novel high internal phase emulsion (HIPE) hydrogels were prepared by oil-in-water emulsion copolymerization of 2-hydroxyethyl methacrylate (HEMA) and N-isopropylacrylamide (NIPAm) in the presence of N,N′-methylene-bis-acrylamide (MBAm) as a crosslinker. Poly(ethylene oxide) based macroinimer was also used as an additional co-surfactant and co-crosslinker. The amount of NIPAm and macroinimer was varied to optimize composition of the hydrogels which sequentially enhanced swelling and metal ion binding capabilities. Swelling properties of all HIPE hydrogels were investigated at different temperatures with a maximum swelling percentage value of ∼2100% determined at 25 °C. Young’s modulus (E) of HIPE hydrogels which is a critical property for understanding their mechanical bevaiors was also calculated and the value increased from 5 to 13 MPa by increasing macroinimer amount. Finally, the use of the prepared HIPE hydrogels in a process to identify the best fitting hydrogel composition was applied as binding materials for the recovery of heavy metals ions such as Pb2+, Cu2+ and Hg2+ from hazardous waste incineration plant effluent. Results deduced a decrease in heavy metal ion binding capacity with increasing temperature in the studied range from 25 °C to 40 °C. Furthermore, heavy metal ion removal based on Venturi scrubber and physicochemical (P/C) plant effluent as wastewater was determined and the maximum binding capacities of the hydrogels were in the magnitude of Cu2+≅ Hg2+ > Pb2+ and Cu2+ > Pb2+ > Hg2+ for Venturi scrubber and P/C plant effluent, respectively.

A mechanistic investigation of the effect of dispersion phase protein type on the physicochemical stability of water–in–oil emulsions

In this study, effects of two animal–based and two plant–based proteins on the stability of W/O emulsions were evaluated. On physical stability, turbiscan stability index values showed that the trend of protein–added emulsion followed the order: whey protein isolate (WPI) < sodium caseinate (CAS) < pea protein isolation (PPI) < chickpea protein isolation (CPI). On chemical stability, the inhibition of lipid oxidation followed the order: CPI < CAS < WPI < PPI. The particle size, zeta potential, ability to increase emulsion viscosity and interfacial adsorption of proteins affected the emulsion physical stability. Among the effects of chemical stability, antioxidant properties, physical barrier effects and transition metal ion binding capacity were crucial for lipid oxidation. In improving the stability of W/O emulsions, we found great potential of CPI and PPI for the future combined application of both and to improve the stability of W/O emulsions.

Synthesis and Characterization of Immobilized Thiolactic Ligand System for the Detoxification of Tannery Wastewater

A porous solid polysiloxane immobilized thiosalicylic acid ligand system has been prepared by hydrolytic polycondensation of tetraethylorthosilicate with a mixture of 3-chloropropyltrimethoxysilane, methanol and sodium hydroxide as a catalyst, gelation formed after 40 min. The product formed was functionalized with excess ethylchloroacetate, triethylamine and immobilized with thiosalicylic acid. The immobilized ligand was characterized using FTIR, the spectrum showed characteristic absorption regions (cm-1) at: 3384 (OH), 1587 to 1722 (C=C, C=O); 900 to 1038 (Si - O) respectively. SEM-EDX showed irregular particle sizes of the polysiloxane matrices with elemental composition (wt %): 3-CPPS; Si (50.45), O (25.02) and Cl (24.57). F - 3CPPS showed, O (58.68), Si (41.32); thiolactic (0.00 of S). The competitive sorption characteristic of the metal ions (Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+) were studied using Microwave Plasma Atomic Emission Spectrophotometer (Agilent MPAES-4200). The immobilized thiolactic ligand exhibits high potential for the extraction of heavy metals in tannery wastewater at pH 6.0, this development would improve the treatment of tannery wastewater at a low cost; batch or column systems of extraction of metal could be employed. Thermodynamic range for the parameters with respect to Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+ yielded negative values for ΔGo, (Cu2+ -(8.650 to 11.962) to Fe2+ -(14.368 to 14.842) KJmol-1; positive values for ΔHo: Zn2+ (0.000) to Cu2+ (21.047) KJmol-1 and ΔSo: Zn2+ (47.421) to Fe3+ (245.869) Jmol1K1 respectively, indicating spontaneous, endothermic reactions and high degree of disorderliness with respect to metal ion binding capacity to the ligand system.

Nanodiamond‐containing polyethyleneimine hybrid materials for lead adsorption from aqueous media

ABSTRACTThis study describes the preparation of new surface‐modified nanodiamond (ND) particles containing urethane‐based hybrid materials by photopolymerization of aliphatic urethane acrylate, trimethylolpropane triacrylate, glycidyl methacrylate monomers, and their usage for lead adsorption from aqueous media. ND and synthesized surface‐modified ND were characterized by atom transfer radical addition Fourier transform infrared spectroscopy (ATR‐FTIR) and scanning transmission electron microscopy analysis. Crosslinked adsorbent nanocomposites were then treated with polyethylene imine and all adsorbent nanocomposites were characterized by ATR‐FTIR, scanning electron microscopy, thermogravimetric analysis, and contact angle measurements. The metal ion binding capacity of the surfaces of the nanocomposites containing high amine content was investigated. The effects of the percentage of functional monomer, pH, and contact time on adsorption, and the interaction of foreign metal ions have been tested. Optimum contact time was found to be 7 h at pH 5. The adsorption capacity of the synthesized nanocomposite adsorbent for lead (II) was determined as 17.12 mg g−1. Langmuir and Freundlich isotherms were used to determine the adsorption behaviors and Langmuir isotherm model was found to be the most suitable model (R2: 0.9988). The amount of adsorption of Pb (II) ions of UV curable adsorbent film prepared in river water samples was investigated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48241.

Functional Characterization of a Type 4 Metallothionein Gene (CsMT4) in Cucumber

The excess amounts of heavy metals are toxic to various physiological processes in plants. Plant metallothioneins (MTs) are low molecular weight, cysteine-rich metal-binding proteins that play important roles in the detoxification of heavy metal ions. In this study, we characterized CsMT4, a plant type 4 MT gene identified in a complementary DNA (cDNA) library prepared from young cucumber (Cucumis sativus) fruit. CsMT4 encodes a 90 amino acid protein with a predicted molecular mass of 9.028 kD. CsMT4 contains 17 cysteine residues in three highly conserved cysteine-rich domains. In contrast to the structures of other MTs, the highly conserved amino acid pattern CxCxxxCxCxxCxC is present in the middle of CsMT4. Furthermore, CsMT4 was markedly induced in various tissues by various concentrations of Cd2+ and Zn2+ (> 1.0 mmol•L−1). Similar to AtMT4b function, heterologous expression of CsMT4 in E. coli could also improved its tolerance to Cd2+ and led to increased uptake of Cd2+, and the rate of Cd2+ uptake was the highest in cells expressing a phytochelatin-like peptide. Our findings demonstrate that CsMT4 might be obviously induced by the metal stress in cucumber, and improves tolerance to Cd ions but not Zn ions when heterologously expressed in E. coli, and suggest that the composition and arrangement of N-terminal Cys-residues in MT4 are associated with their binding capacity and preference for different metal ions.

Characterization analysis and heavy metal-binding properties of CsMTL3 in Escherichiacoli.

Members of the metallothionein (MT) superfamily are involved in coordinating transition metal ions. In plants, MT family members are characterized by their arrangement of Cys residues. In this study, one member of the MT superfamily, CsMTL3, was characterized from a complementary DNA (cDNA) library from young cucumber fruit; CsMTL3 is predicted to encode a 64 amino acid protein with a predicted molecular mass of 6.751 kDa. Phylogenetic analysis identified it as a type 3 family member as the arrangement of N‐terminal Cys residues was different from that of MT‐like 2. Heterologous expression of CsMTL3 in Escherichia coli improved their heavy metal tolerance, particularly to Cd2+ and Cu2+, and led to increased uptake of Cd2+ and Cu2+; increased uptake was also observed for cells expressing Arabidopsis thaliana metallothionein 3 (AtMT3) and phytochelatin‐like (PCL), with greatest uptake in PCL‐expressing cells. These findings demonstrate that CsMTL3 can improve metal tolerance, especially for Cd2+ ions, when heterologously expressed in E. coli, and suggest that the composition and arrangement of N‐terminal Cys residues are associated with binding capacity and preference for different metal ions.

Gamma radiation-induced preparation of poly(1-vinyl-2-pyrrolidone-co-sodium acrylate) for effective removal of Co(II), Ni(II), and Cu(II)

Clearing the water and wastewater from toxic heavy metals has received attentions from many researchers and scientists. In this study, poly(1-vinyl-2-pyrrolidone-co-sodium acrylate), P(VP-SA), was prepared by gamma radiation-induced copolymerization of VP and SA and utilized for the effective removal of cobalt(II), nickel(II), and copper(II) from their aqueous solutions. Effect of comonomer composition and concentration besides the adsorbed dose on the conversion percentage and the reduced viscosity was studied. The formed copolymer was characterized using Fourier transform infrared and gel permeation chromatography analysis, and the thermal stability was examined using thermogravimetric analysis. The influence of the adsorption conditions such as contact time, pH, copolymer concentration, and initial metal ion concentration on the metal ion binding capacity was tested. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion adsorption models were used to explain the adsorption kinetics. Finally, the equilibrium adsorption data fitted well with Langmuir isotherm model, and the maximum adsorption amounts on P(VP-SA) copolymer calculated by Langmuir equation were 425.60, 93.01 and 450.81 mg g−1 for Cu+2, Ni+2, and Co+2, respectively.

Reduction in albumin binding function following liver resection in patients with and without cirrhosis

Background: The aim of this study is to investigate effects of liver resection on albumin binding function in patients with and without cirrhosis. Methods: An observational study was performed on 42 patients with cirrhosis and hepatocellular carcinoma (HCC), and 17 patients without cirrhosis diagnosed with hepatic cavernous hemangioma, all of whom underwent tumor resection. Control group consisted of 50 healthy volunteers. Albumin metal ion binding capacity was assayed as ischemia-modified albumin transformed (IMAT, equal to 1-IMA), and albumin fatty acid binding strength was also tested. All indicators were measured 1 day before and 1, 3, 7 days after surgery. Results: Preoperative IMAT was significantly higher in healthy volunteers than cirrhotic patients (P=0.02), but not than non-cirrhotic patients (P=0.79). Following surgery, a prolonged and sharp reduction was observed in cirrhotic patients; whereas, in non-cirrhotic patients, the result rose sooner and faster. Albumin fatty acid binding strength in both operated groups decreased for the first 3 days after hepatectomy, then both increased to preoperative levels by day 7. Albumin fatty acid binding strength was higher in non-cirrhotic than cirrhotic patients at all time points. Conclusions: This is the first study to show that albumin binding function decreases following liver resection in patients with and without cirrhosis. It is more objective than albumin concentration and less affected by albumin infusion. It may be an important indicator of liver function.

From Food Additive to High-Performance Heavy Metal Adsorbent: A Versatile and Well-Tuned Design

A biosourced, cross-linked hydrogel-type heavy metal adsorbent is presented. Various factors such as the highly efficient chemical interactions, the various network structures, the decreased energy consumption during cross-linking, and the negligible amount of generated waste are considered when designing the adsorbent. The widely applied, naturally occurring food additive δ-gluconolactone is studied as a building block for the adsorbent. Aminolysis reactions were applied to form linear dimer precursors between diamines and δ-gluconolactones. The abundant hydroxyl groups on the dimers from δ-gluconolactone were fully exploited by using them as the cross-linking sites for reactions with ethylenediaminetetraacetic dianhydride, a well-known metal-chelating moiety. The versatility of the adsorbent and its metal-ion binding capacity is well tuned using dimers with different structures and by controlling the feed ratios of the precursors. Buffers with different pH values were used as the conditioning media to e...

Albumin Binding Function: The Potential Earliest Indicator for Liver Function Damage.

Background. Currently there is no indicator that can evaluate actual liver lesion for early stages of viral hepatitis, nonalcoholic fatty liver disease (NAFLD), and cirrhosis. Aim of this study was to investigate if albumin binding function could better reflect liver function in these liver diseases. Methods. An observational study was performed on 193 patients with early NAFLD, viral hepatitis, and cirrhosis. Cirrhosis patients were separated according to Child-Pugh score into A, B, and C subgroup. Albumin metal ion binding capacity (Ischemia-modified albumin transformed, IMAT) and fatty acid binding capacity (total binding sites, TBS) were detected. Results. Both IMAT and TBS were significantly decreased in patients with NAFLD and early hepatitis. In hepatitis group, they declined prior to changes of liver enzymes. IMAT was significantly higher in cirrhosis Child-Pugh class A group than hepatitis patients and decreased in Child-Pugh class B and class C patients. Both IMAT/albumin and TBS/albumin decreased significantly in hepatitis and NAFLD group patients. Conclusions. This is the first study to discover changes of albumin metal ion and fatty acid binding capacities prior to conventional biomarkers for liver damage in early stage of liver diseases. They may become potential earliest sensitive indicators for liver function evaluation.

A Genetically Modified Tobacco Mosaic Virus that can Produce Gold Nanoparticles from a Metal Salt Precursor.

We genetically modified tobacco mosaic virus (TMV) to surface display a characterized peptide with potent metal ion binding and reducing capacity (MBP TMV), and demonstrate that unlike wild type TMV, this construct can lead to the formation of discrete 10–40 nm gold nanoparticles when mixed with 3 mM potassium tetrachloroaurate. Using a variety of analytical physicochemical approaches it was found that these nanoparticles were crystalline in nature and stable. Given that the MBP TMV can produce metal nanomaterials in the absence of chemical reductants, it may have utility in the green production of metal nanomaterials.

Adsorption Characteristics of Copper (II) Ions from Aqueous Solution onto Ionic Cross-linked Pva/P(Aam-Nipaam) Core-shell Nanogels

Core-shell nanogels adsorbent were investigated for copper (II) removal from aqueous solution, consisting of poly(vinyl alcohol) (PVA) core and poly(acrylamide- N-isopropylacrylamide/) p(AAm-NIPAm) shell particles. Various factors affecting the adsorption capacity, such as swelling, pH, time, initial ion concentration, and different metal ions on the metal ion binding capacity for nanogel, was also tested. The selectivity of the nanogels toward the different metal ions tested was Cu2+> Ni2+ > Pb2+. The results show that the adsorption of nanogels mainly depends on pH, and the maximum adsorption was obtained at a pH of 6.0. The adsorption capacity of Cu+2 was 126 mg/g obtained under simple and fast experimental conditions, the effect of different mole ratios of p(AAm-NIPAm) shells thickness were synthesized, to determine the maximum metal uptake. The core-shell nanogels were characterized by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and transmission electron microscope (TEM). It was found that adsorbed Cu+2 ions on PVA/p(AAm-NIPAm) nanogels can be effectively desorbed by acid stripping with 0.1 mol/L HCl resulted in 96% Cu+2 recovery for the nanogels; this shows the ability of the nanogels to be reused, upon drying between treatments. The nanogels adsorbent can be regenerated after releasing of Cu+2 and reused three times effectively. All the experimental result exhibited good matches with the Freundlich isotherm and followed pseudo-second-order kinetics. The mechanism of adsorption of Cu+2 onto PVA/p(AAm-NIPAm) nanogels is proposed.

UV Cured Polymeric Optical Fluorescence Sensor for the Determination of Au (III)

SummaryThe recognition and sensing of the biologically and environmentally important metal ions has emerged as a significant goal in the field of chemical sensors in recent years. Among the various analytical methods, fluorescence has been a powerful tool due to its simplicity, high detection limit and application to bio imaging.In this study, UV cured polymeric optical sensor for Au (III) ion based on a fluorescence membrane has been developed. The response characteristics of the sensor including dynamic range, pH effect and response time were systematically investigated. The influences of the conditions such as pH, response time on the metal ion binding capacity of membrane were also tested.

Oil palm biomass as an adsorbent for heavy metals.

Many industries discharge untreated wastewater into the environment. Heavy metals from many industrial processes end up as hazardous pollutants of wastewaters.Heavy metal pollution has increased in recent decades and there is a growing concern for the public health risk they may pose. To remove heavy metal ions from polluted waste streams, adsorption processes are among the most common and effective treatment methods. The adsorbents that are used to remove heavy metal ions from aqueous media have both advantages and disadvantages. Cost and effectiveness are two of the most prominent criteria for choosing adsorbents. Because cost is so important, great effort has been extended to study and find effective lower cost adsorbents.One class of adsorbents that is gaining considerable attention is agricultural wastes. Among many alternatives, palm oil biomasses have shown promise as effective adsorbents for removing heavy metals from wastewater. The palm oil industry has rapidly expanded in recent years, and a large amount of palm oil biomass is available. This biomass is a low-cost agricultural waste that exhibits, either in its raw form or after being processed, the potential for eliminating heavy metal ions from wastewater. In this article, we provide background information on oil palm biomass and describe studies that indicate its potential as an alternative adsorbent for removing heavy metal ions from wastewater. From having reviewed the cogent literature on this topic we are encouraged that low-cost oil-palm-related adsorbents have already demonstrated outstanding removal capabilities for various pollutants.Because cost is so important to those who choose to clean waste streams by using adsorbents, the use of cheap sources of unconventional adsorbents is increasingly being investigated. An adsorbent is considered to be inexpensive when it is readily available, is environmentally friendly, is cost-effective and be effectively used in economical processes. The advantages that oil palm biomass has includes the following:available and exists in abundance, appears to be effective technically, and can be integrated into existing processes. Despite these advantages, oil palm biomasses have disadvantages such as low adsorption capacity, increased COD, BOD and TOC. These disadvantages can be overcome by modifying the biomass either chemically or thermally. Such modification creates a charged surface and increases the heavy metal ion binding capacity of the adsorbent.

Adsorption of Ag (I) Ions from Aqueous Solutions Using Photocured Thiol-Ene Hydrogel

In this present work, we reported the adsorption and recovery studies of a P(Penta3MP4/PEG-DA/HEMA) thiol-ene based hydrogel. Real-time infrared spectroscopy technique was used to identify the photopolymerization kinetics of thiol-ene based formulations. The chemical composition and surface morphology of hydrogels were also characterized. The influence of the adsorption conditions such as pH, hydrogel formulations, contact time, initial metal ion concentration, and foreign metal ions on the metal ion binding capacity of hydrogel, were tested. Both the Langmuir and Freundlich isotherm models were applied to the method. The reusability of the hydrogels and the usability of the hydrogels for preconcentration studies were also investigated. The analytical parameters of the method were calculated and the recovery of silver ions from waste radiographic films was also applied to the hydrogels.

Fe(III)–resorcylate as a spectrophotometric probe for phospholipid–cation interactions

A simple spectrophotometric microplate assay that allows quantification of the interaction between phospholipids and metal ions or other small cationic compounds has been developed. The assay is based on the competition of the phospholipids for the Fe3+ ion in the purple-colored Fe(III)–γ-resorcylate complex and for other cations. To compare the binding affinities of several cation–phospholipid interactions, K0.5 values were derived from binding curves constructed by determination of the absorbance of the Fe(III)–γ-resorcylate at 490nm as a function of the cation concentration. The assay was used to analyze the binding of lanthanide ions, calcium ions, and amines (hydrochlorides of ethanolamine, spermidine, and hexyltrimethylammonium chloride) to small unilamellar vesicles (SUVs) and mixed micelles containing anionic lipids such as phosphatidic acid and phosphatidyl-p-nitrophenol. The method was evaluated by fluorescence measurements with Eu3+ ions as tracer. Lanthanide ions such as La3+ and Ce3+ ions showed K0.5 values smaller by one to two orders of magnitude compared with Ca2+ ions. In the presence of increasing amounts of detergents such as Triton X-100, the method also reflected transitions from SUVs to micelles. The binding capacity for metal ions was higher for phospholipid-containing micelles than for the corresponding SUVs.

Application of Crosslinked Ionic Poly(Vinyl Alcohol) Nanogel as Adsorbents for Water Treatment

Core-shell smart ionic nanogels based on poly(vinyl alcohol) (PVA) core and poly(N-isopropylacrylamide/acrylic acid) p(NIPAm-AAc) shell particles were successfully synthesized through a one-step surfactant-free emulsion polymerization method (SFEP). Different mole ratios of p(NIPAm-AAc) shells were synthesized. The morphologies of PVA/p(NIPAm-AAc) nanogels were investigated by transmission electron microscope (TEM). The data showed the formation of spherical nanoparticles and well-defined core-shell nanogels. PVA/p(NIPAm-AAc) core-shell nanogels were applied as a novel polymeric adsorbent to remove heavy metal pollutants from aqueous solution. Copper(II) (Cu2+) ions were selected as the target pollutant to evaluate these nanoparticles’ adsorption capability. The influence of the uptake conditions such as pH, weight ratio of nanoparticles, time, initial feed concentration, and adsorption temperature on the metal ion binding capacity of nanogels was also tested. Adsorption equilibrium data were calculated according to Langmuir and Freundlich isotherms. It was found that the sorption of Cu2+ was better suited to the Freundlich adsorption model than the Langmuir adsorption model. Also, the selectivity of the nanogels toward the different metal ions such lead (Pb2+) and cadmium (Cd2+) were tested. The maximum of Cu2+ ions adsorbed on to PVA/p(NIPAm-AAc) core-shell nanogels adsorbent was 94 mg/g obtained under simple and fast experimental conditions, indicating these nanogels can be used as effective and practical polymeric adsorbents.

Synthesis of novel aniline immobilized silica gel for the selective extraction of Cr(III)

Aniline moiety was immobilized on the surface of silica gel (SG) through functionalizing the later by 3-chloropropyl trimethoxysilane (3-CPTS). The aniline immobilization was confirmed by chemical, Fourier transform infrared (FTIR), thermo gravimetric analysis (TGA), and scanning electron microscopy (SEM). Solid phase extraction (SPE) property of the synthesized product was studied in terms of Cr(III) uptake by batch and column methods. Metal ion adsorption and its isotherm, kinetic and thermodynamic parameters were evaluated. The mechanistic path involved in up taking metal ion has been suggested. The Cr(III) binding capacity was found to be 8.7 mg g−1 at trace level of chromium in aqueous medium. The presence of chloride ion improved the metal ion binding capacity as well as selectivity to a significant extent. The developed material and the selective extraction method were tested by applying it in real samples and the results were compared with the reported values.