Ion Imprinted Polymer Particles Research Articles

Design of an histidine-based imprinted polymer as a selective receptor of copper(II) for its detection in seawater

A protein-inspired ion-imprinted polymer (IIP) was used as an additive in a carbon paste electrode for the selective determination of copper(II) in water samples. The imprinted polymer was synthesized by precipitation polymerization of a functional monomer, methacrylamido-L-histidine (MAH), based on an amino acid, L-histidine, with ethylene glycol dimethacrylate (EGDMA) as crosslinker. The corresponding non-imprinted polymer (NIP) and a copolymer containing EGDMA and methyl methacrylate (MMA) (in the same proportions as MAH in the NIP) were also prepared in similar conditions as the IIP. The polymer particles were first chemically characterized by 13C CP-MAS NMR and FT-IR and the presence of MAH was confirmed by the colorimetric Pauly's test. It was shown by SEM and adsorption/desorption of nitrogen that the IIP and the NIP present similar morphological properties. The copper(II) binding properties of the polymers were also studied in a batch adsorption experiment, and an imprinting effect was observed for the IIP. This polymer was shown to possess binding cavities selective towards copper(II) versus common interferents (iron(III), zinc(II) and lead(II)), when compared to the NIP and to the poly(EGDMA-co-MMA). A carbon paste working electrode was prepared with the IIP particles and a limit of detection of 59 nmol/L for copper(II) was determined in a potassium phosphate buffer (0.1 M, pH = 7). The determination of copper(II) was not affected by the presence of a 50-fold excess of iron(III), zinc(II) and lead(II). Finally, the copper concentration in a real seawater was estimated to be 0.12 μmol/L, in full agreement with a measurement by polarography which was used as a reference method.

New ion-imprinted polymer for selective removal of Cu2+ ion in aqueous solution using extracted Aloe vera leaves as a monomer

The objective of this project is to create a unique type of polymer known as an ion imprinted polymer (IIP) and a non-imprinted polymer (NIP) utilizing natural waste biosorbent materials. One example of this type of waste is Aloe vera, a plant with many medicinal uses that is grown globally. Aloe vera is considered one of the most valuable medicinal plants with a wide range of applications. Extracted Aloe vera was used as functional monomers for the first time to prepare new IIPs, epichlorohydrin, and Cu2+ ion as the cross-linking agent and template, respectively. The NIP was also synthesized for comparison, without the use of the Cu2+ salt. Following polymerization, the IIP particles were cleansed of template ions through a 0.1 M EDTA leaching process, resulting in the formation of cavities within the particles, these cavities in the polymer provide selective linking zones for these specific template ions. The synthesized IIPs were characterized using the most recent identification instruments. The experimental parameters for adsorption, such as pH of a solution, contact time, initial copper concentration, adsorbent dosage, and temperature have been optimized. The most effective conditions for metal adsorption onto the ionic imprinted polymer were found to be a pH of 8.0, a temperature of 30 °C, a concentration of 0.03 g/100 mL, and a contact time of 50 min. Based on the ANOVA statistical value, the adsorption of Cu2+ ion on IIP is significant with very low probability (p) values (<0.001).The Langmuir isotherm model and a second-order reaction were both used in the adsorption process. According to thermodynamic characteristics, Cu2+ adsorption over IIPs and NIP was an endothermic, spontaneous process. Compared to NIP, the imprinted polymer exhibits a significantly better capacity and selectivity for Cu2+ adsorption, the maximum removal percentage of IIPs and NIP was 96.02 % and 74.3 % respectively. Moreover, the research showed that ion imprinting can be a promising technique for preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metals (Co2+, Cd2+, Ni2+, Zn2+, Fe2+, and Pb2+) The most important point for this new Cu2+-IIPs was shown superior reusability up to 8 cycles with small decrees in uptake capability.

Ultra-preconcentration technique for the determination of thallium (I) in water samples by a combination of thallium (I)-imprinted polymer and vortex-assisted liquid–liquid microextraction

In this research study, thallium(I)-imprinted polymer and vortex-assisted liquid–liquid microextraction methods were used for ultra-preconcentration and extraction of thallium (I) ions for consecution in ultra-trace level in aqueous solution. In the first extraction step, ion-imprinted polymer particles were applied as a selective technique. Next, the eluted solution is used for extraction with the vortex-assisted liquid–liquid microextraction technique. There are several factors that have an effect on the two processes. They were studied to improve the separation performance. The advantages of the method are good linear range (0.015–0.8 ngmL−1), low detection limit (2.1 pgmL−1), and ultra-trace level determination thallium (I) ions. The new procedure has a high-preconcentration factor (PF = 2000) for determining of thallium (I) ions in water samples. The relative standard deviation for five replicate analyses of 0.1 ng mL−1 of thallium(I) was 4.8%. The recovery percentage of thallium was calculated from the electrothermal atomic absorption spectrometry results. The thallium(I)-imprinted polymer and vortex-assisted liquid–liquid microextraction method was successfully employed to determine thallium (I) ions in industrial wastewater, well water, and urban sewage samples with a satisfactory recovery in the range of 90 to 98%.

Separation-preconcentration and ultra trace lead determination in the environmental sample by a combination of ion-imprinted polymer and solidification of floating organic drop microextraction

ABSTRACT The ion-imprinted polymer combined with the solidification of floating organic drop microextraction has been developed as an ultra-pre-concentration technique to determine lead ions in real samples. In ion-imprinted polymer – solidification of floating organic drop microextraction, lead was adsorbed from a large volume of aqueous samples (500 mL) into 100 mg of the ion-imprinted polymer sorbent. After the elution of lead ions from the sorbent by using nitric acid, the solidification of floating organic drop microextraction technique was performed on the obtained solution. Several important extraction parameters, such as weight of ion-imprinted polymer (mg), pH, uptake time (min), desorption time (min), HNO3 desorption volume (mL) aqueous-phase volume (mL), were studied and optimised. The ion–imprinted polymer particles were characterised by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). The new method (SPE–SFODME) provided an ultra-enrichment factor (5000) for lead. The calibration graphs were linear in the range of 5–200 ng L−1. The optimum conditions for the method were as follows: pH of solution, 7.5; weight of ion-imprinted polymer, 100 mg; type and concentration of eluent, HNO3 1 M; volume of eluent, 1 mL; sorption time, 25 min; desorption time, 15 min. Under optimum conditions, the limit of detection (LOD) was 1 ng L−1 for lead and relative standard deviation (RSD %) for five replicate determinations of 10 ng L−1 for lead was 6.5%. The results for the determination of lead ions in reference materials, tap water, ground vegetables, butter and flour wheat demonstrated the accuracy, recovery and applicability of the presented method.

Evaluation of porogen factors for the preparation of ion imprinted polymer monoliths used in mercury removal.

In the present study, ion imprinted polymer monoliths (IIPMs) were developed to overcome the limitations of ion imprinted polymer particles (IIPPs) used for the removal of Hg(II) ions from waste water samples. The adsorbents preparation, characterization and Hg(II) removal were very well reported. The IIPMs on porogen optimization was prepared using the molding technique with Hg(II) as a template ion, [2-(methacryloyloxy)ethyl]trimethylammonium cysteine (MAETC) as ligand, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylamide (EGDMA) as cross-linker, benzoyl peroxide as an initiator and methanol and acetonitrile as porogen in the polypropylene tube (drinking straw) as mold. The IIPMs prepared with higher volumes of porogen were indicated to have a good adsorption rate for the Hg(II) removal along with good water permeability and larger porosity as compared to a lower volume of porogen. The IIPMs prepared using the binary porogen were able to improve the porosity and surface area of the monolithic polymers as compared to the single porogen added IIPMs. Finally, we indicate from our analysis that the IIPM having the efficient capacity for the Hg(II) ions is easy to prepare, and has higher water permeability along with high porosity and high adsorption capacity and all these factors making it one of the suitable adsorbent for the successful removal of Hg(II) ions.

Selective solid phase extraction of lanthanides from tap and river waters with ion imprinted polymers

For the first time, an ion imprinted polymer (IIP) able to selectively extract simultaneously all the lanthanide ions was successfully synthesized in acetonitrile using Nd3+ as a template ion, methacrylic acid as a complexing monomer, and ethylene glycol dimethacrylate as a cross-linker. A non-imprinted polymer (NIP) was synthesized under the same conditions as those of the IIP, but in the absence of the template ion. After the removal of the template ions, grounding and sieving, the IIP particles were packed in solid phase extraction (SPE) cartridges. The selectivity of the IIP was evaluated by comparing its behavior with the one of the NIP. Each SPE step (percolation, washing, and elution) was optimized in order to find the best compromise between the selectivity and the extraction recoveries. Using the optimized SPE conditions, the extraction recoveries of eight lanthanide ions representative of the lanthanide family were higher than 77% with an average value of 83% with the IIP, whereas, in the case of the NIP, they ranged between 14 and 36% and they were below 3% for the interfering ions from alkali, transition, and post-transition metal families with the IIP. A first evaluation of the reproducibility of the SPE profiles was carried out by performing statistical tests on the data obtained with several cartridges filled with particles obtained from two different IIP and NIP syntheses. Promising results were obtained. The specific capacity, i. e. the adsorption capacity of Nd3+ ions by the specific cavities of the imprinted polymer, was about 9 mg of Nd3+ per gram of IIP (60 μmol g−1), which is more than enough for the extraction of the lanthanide ions at trace levels. The breakthrough volume was about 1 mL per mg of IIP, leading to an enrichment factor of 15, which allows not only to selectively extract the lanthanides but also to concentrate them. Finally, the imprinted polymer was successfully used to selectively extract lanthanides from tap and river waters spiked at 1 μg L−1.

Electrochemical sensor based on lead ion-imprinted polymer particles for ultra-trace determination of lead ions in different real samples

In this paper, a self-manufactured lead(ii)-selective electrode, which was based on the use of lead(ii) ion imprinted polymer particles (IIPs) to detect lead ions, was studied using differential pulse voltammetry.

Preparation of a K(+) -imprinted polymer for the selective recognition of K(+) in food samples.

An analytical method is reported for the preparation of K(+) -imprinted nanoparticles using cryptand 222 as the complexing agent, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinker and 2,2'-azobisisobutyronitrile as the radical initiator. The prepared particles have a diameter of 200-250 nm. The maximum adsorption capacity of potassium ion-imprinted polymer particles was 120 μmol/g. The optimum pH for quantitative extraction was 9.0. The nature of the eluent, eluent concentration, adsorption and desorption times, weight of the polymer material, aqueous phase, and desorption volumes were also studied. The relative selectivity coefficients of K(+) /Li(+) , K(+) /Na(+) , K(+) /Rb(+) and K(+) /Cs(+) were 48.10, 4.80, 29.70, and 43.4, respectively. The relative standard deviation and limit of detection of the method were obtained 1.61% and 4.62 ng/L, respectively. Finally, the method was applied for the determination of potassium ions from different samples using flame photometry.

Synthesis and application of a novel nanostructured ion-imprinted polymer for the preconcentration and determination of thallium(I) ions in water samples

A novel synthesized nanostructured ion-imprinted polymer (IIP) was investigated for the determination of trace amount of thallium(I). For this purpose, the thallium(I) IIP particles were synthesized using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, methyl-2-[2-(2-2-[2-(methoxycarbonyl) phenoxy] ethoxyethoxy) ethoxy] benzoate as the chelating agent and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The prepared IIP particles were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA). Various experimental factors such as pH, the amount of IIP particles, sorption and desorption time, sample volume, elution condition, and potentially interfering ions systematically examined. Under the optimum conditions, a sensitive response to Tl(I) within a wide concentration range (0.05–18μgL−1) was achieved. The limit of detection (LOD, 3Sb/m) was 6.3ngL−1. The maximum adsorption capacity of the novel imprinted adsorbent for Tl(I) was calculated to be 18.3mgg−1. The relative standard deviation (RSD) for eight replicate detections of 0.1μgL−1 of thallium(I) was found to be 4.0%. An enrichment factor (EF) of 100 was obtained by this method. The proposed technique was successfully applied to monitoring thallium in different water samples and the certified reference material.

Synthesis and Characterization of Nanopore MoVI-Imprinted Polymer and Its Application as Solid Phase for Extraction, Separation and Preconcentration of Molybdenum Ions from Water Samples

The purpose of this study is to prepare a new ion imprinted polymer for MoVI with high selectivity. Ion-imprinted polymer (IIP) particles were synthesized by thermally copolymerization. For the synthesis of the ion imprinted polymer, the ion pair of (MoVI-thiocyanate) and NR4+ was used. The ion pair was precipitated in an aqueous phase and then dissolved in acetonitrile as a porogen. The imprinted ion was removed using 10% (v/v) methanol in HCl (0.5 mol L-1). The unleached and leached IIP particles were characterized by infrared spectroscopy, thermogravimetric analysis, surface area analysis, scanning electron microscopy and energy dispersive X-ray analysis. The use of the new MoVI-IIP in solid phase extraction revealed a maximum adsorption capacity of 3.77 mg MoVIper gram of MoVI-IIP in optimum conditions of extraction. The selectivity coefficients of the IIP for Mo in comparison with other metal ions were also evaluated. The proposed Mo-IIP was successfully applied for MoVI determination in different types of water samples.

Biopolymer based ion imprinting cryogel traps for the removal of Tl(I)

ABSTRACTThe aim of this study is to prepare supermacroporous cryogel with embedded ion imprinted polymer (IIP) particles which can be used for the selective removal of Tl(I) from aqueous solution. In the first step, Tl(I) has complexed with chitosan and crosslinked with ephychlorohydrin. In the second step, the supermacroporous poly(hydroxyethyl methacrylate) (PHEMA) cryogel with embedded IIP particles [PHEMA/MIP composite cryogel] which have been produced by free radical polymerization initiated by N,N,N’,N’-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in ice bath. The template, Tl(I), has been removed from the polymer using 0.1 M EDTA solution. The cryogel is characterized by swelling test, scanning electron microscopy, and Fourier transform infrared spectroscopy. The effective parameters on Tl(I) adsorption process have evaluated by investigating the dependency of the adsorption capacity on flow-rate, Tl(I) concentration and contact time. The maximum adsorption capacity of Tl(I) ions has been found to be 1.55 µgg−1. The selectivity of the IIP biopolymer cryogel has investigated by competitive adsorption of Cd(II), Cu(II), K(I), and Fe(II). The relative selectivity coefficients of IIP biopolymer cryogel are 3.98 and 62.5 for Cd(II) and Cu(II), respectively. The IIP biopolymer cryogel could be used many times without any significant decrease in the adsorption capacity. As a conclusion it can be said that the IIP biopolymer cryogel could be used for specific separation of Tl(I) ions from nuclear, industrial, and environmental waste.

Synthesis and application of ion-imprinted polymer for extraction and pre-concentration of iron ions in environmental water and food samples

In this work, a novel Fe(III) ion imprinted polymer as a sorbent for extraction of iron ions from different samples was synthesized. Precipitation of thermal copolymerization was used for preparation of polymeric sorbent. In this technique, methacrylic acid, ethylene glycoldimethacrylate, 2,2′-azobisisobutyronitrile and (DHBPT)2 {(DHBPT)2=3,6-bis (3,5-dimethyl-1-H-pyrzol-1-yl)-1,2-dihydro-1,2,4,5-tetrazine)} were used as monomer, cross-linker, initiator and ligand, respectively, in the presence of Fe(III) ions and ethanol as a porogenic solvent. Moreover, control polymer (NIP) particles were similarly prepared without the Fe(III) ions. XRD, FT-IR, SEM and nitrogen adsorption–desorption techniques have been used to characterization of these prepared polymeric samples. Iron ion imprinted polymer particles, abbreviated as Fe(III)–IIP, were leached with 50mL of HCl (50% (v/v)). Absorption capacity for ion imprinted polymer was calculated about 40.41mg·g−1. Per-concentration of iron ion was investigated as a function of pH, weight of IIP, adsorption and desorption times, and volumes of sample. FAAS technique was used to determination of Fe(III) ion in the foods and waters samples.

Selective sorption behavior of metal(II) ion-imprinted polymethacrylate microspheres synthesized via precipitation polymerization method

Metal methacrylate complex was synthesized from methacrylic acid and metal carbonate to prepare metal ion-imprinted polymer (MIIP) particles by the precipitation polymerization method. Three types of metal ions, Cu(II), Ni(II), and Pb(II), were used as the template ions in this synthesis. The produced MIIP particles were spherically well-defined with 0.5–2 μm diameter in the order of Cu(II)-MIIP>Ni(II)-MIIP>Pb(II)-MIIP. The imprinted polymers exhibited a much higher adsorption capacity and selectivity toward the target (template) ion than other competitive metal ions. The MIIP particles, Cu(II)-MIIP, Ni(II)-MIIP, and Pb(II)-MIIP, synthesized in this study guaranteed the selective separation of the target metal ion from the mixtures, although their competitive strengths of the adsorption capacity and selectivity were different.

Synthesis and application of ion-imprinted polymer nanoparticles for the determination of nickel ions

Novel Ni(II) ion-imprinted polymers (Ni-IIP) nanoparticles were prepared by using Ni(II) ion–1,5-diphenyl carbazide (DPC) complex as the template molecule and methacrylic acid, ethylene glycol dimethacrylate (EGDMA) and 2,2′-azobisisobutyronitrile (AIBN) as the functional monomer, cross-linker and the radical initiator, respectively. The synthesized polymer particles were characterized physically and morphologically by using infrared spectroscopy (IR), thermo gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques. Some parameters such as pH, weight of the polymer, adsorption time, elution time, eluent type and eluent volume which affects the efficiency of the polymer were studied. The preconcentration factor, relative standard deviation, and limit of detection of the method were found to be 100, 1.9%, and 0.002μgmL−1, respectively. The prepared ion-imprinted polymer particles have an increased selectivity toward Ni(II) ions over a range of competing metal ions with the same charge and similar ionic radius. The method was applied to the determination of nickel in tomato and some water samples.

Synthesis and Selective Sorption Behavior of Pt(IV) Ion-Imprinted Polymer Particles

Pt(IV) ion-imprinted polymer (Pt(IV)-IIP) was synthesized in the form of porous particles with dimensions of 100–400 μm by the copolymerization of divinylbenzene and styrene in the presence of self-assembled chelates of 4-vinylpyridine and dimethylglyoxime functional monomers along with Pt(IV) ions. The chemical structure of Pt(IV)-IIP was identified by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy. The pore size and structure of Pt(IV)-IIP was characterized by Brunauer–Emmett–Teller analysis and scanning electron microscope. The effects of pH and the initial concentration of Pt(IV) on the selective adsorption behavior for the template ion was investigated using flame atomic absorption spectroscopy. Compared to nonimprinted polymer particles, the Pt(IV)-IIPs illustrated excellent selectivity toward the template ion, Pt(IV), over other competitive ions such as Ni(II), Cu(II), and Pd(II). The selectivity coefficients (α) of Pt(IV)/Ni(II), Pt(IV)/Cu(II), Pt(IV)/Zn(II), and Pt(IV)/Pd(II) were 330.27, 359.89, 463.91, and 4.85, respectively. The study on the selective separation of Pt(IV) from the spent catalyst solution revealed the potential application of Pt(IV)-IIP particles in the practical industry.

A novel lead imprinted polymer as the selective solid phase for extraction and trace detection of lead ions by flame atomic absorption spectrophotometry: Synthesis, characterization and analytical application

A novel ion imprinted polymer as the selective solid phase combined with flame atomic absorption spectrometry (FAAS) was applied for preconcentration and determination of lead in real samples. In the first step, Pb(II)-IIP was synthesized by copolymerization of 2-vinyl pyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, 2,2-azobisisobutyronitrile as the initiator that imprinted with Pb(II) as the template ion, 2-amino pyridine as the ligand. Subsequently, the imprinted Pb(II) was completely removed by leaching the dried and powdered imprinted polymer with HCl (2molL−1). This polymer was characterized by Fourier Transform Infrared (FT-IR) spectrometer. The effect of different variables on the extraction efficiency such as type and volume of eluent for extraction, solution’s pH for adsorption, sorption and desorption times was evaluated. Under the optimum conditions: type of eluent, HCl (2molL−1); volume of eluent, 5mL; solution’s pH for sorption, 5; sorption time, 90min; desorption time, 125min and breakthrough volume of 750mL were obtained. Preconcentration factor of the method was about 150. The limit of detection was obtained 0.75μgL−1 and a dynamic linear range (DLR) of 3–150μgL−1 was found. The maximum sorption retention capacity of Pb(II) ions on the imprinted polymer was 85.6mgg−1. The prepared ion-imprinted polymer particles have an increased selectivity toward Pb(II) ions over a range of competing metal ions with the same charge and similar ionic radius. Performance of the present method was evaluated for extraction and determination of Pb(II) in water samples at microgram per liter concentration and satisfactory results were obtained (RSD=2.7%).

Synthesis and selective recognition property of Ni2+‐imprinted microporous polymer beads

Nickel ion‐imprinted polymer (IIP) was synthesized from dimethylglyoxime and 4‐vinyl pyridine monomers. These functional monomers were self assembled with the Ni2+ template and then copolymerized with divinylbenzene and ethylene glycol dimethacrylate crosslinkers in toluene porogen via suspension polymerization. Imprinting was achieved by removing the template ion from the copolymers by extensive washing. The IIP particles produced were 300–700 µm in diameter and were spherical. The chemical and physical structures were characterized by Fourier transform infrared spectroscopy, energy dispersive X‐ray spectroscopy, and Brunauer–Emmett–Teller analysis. The adsorption capacity and kinetics, and separation selectivity were investigated using atomic adsorption spectroscopy in batch adsorption operation mode. The Ni2+‐imprinted polymers showed excellent adsorption ability and selective separation property. The adsorption capacity for Ni2+ was 320 µmol/g, and the selectivity factors (α) for Cu2+, Zn2+, Fe2+, and Cd2+ were 6, 11, 12, and 27, respectively. The adsorption capacity and separation selectivity were affected by the environmental pH, as the protonation easily took place in acidic condition. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Synthesis and application of ion-imprinted polymer particles for solid-phase extraction and determination of trace scandium by ICP-MS in different matrices

A novel Sc(III) ion-imprinted polymers (Sc-IIP) sorbent was prepared by using Sc(III) ion-8-hydroxyquinoline complex as the template molecule and methacrylic acid, ethylene glycol dimethacrylate (EGDMA) as the functional monomer and cross-linker, respectively. In the present work, a new method using a microcolumn packed with Sc-IIPs as a solid-phase extraction adsorbent was developed for the selective separation and preconcentration of trace amounts of scandium(III) prior to the determination by inductively coupled plasma mass spectrometry. Various factors influencing the separation and preconcentration of trace scandium, such as pH, sample flow rate and breakthrough volume, elution concentration and volume were investigated in detail. Scandium can be quantitatively retained on the IIPs sorbent at pH 4.0–6.5 from sample volume up to 300 mL and then eluted efficiently with 5 mL 3% HNO3 solution, therefore an enrichment factor of 60 was accomplished. The maximum adsorption capacity of the ion-imprinted and non-imprinted sorbent was 12.8 mg g−1 and 3.5 mg g−1, respectively. Under optimal conditions, the detection limit for scandium was 0.013 ng L−1 in water, 0.46 ng g−1 in geological sample, and the relative standard deviation was 3.2% (n = 11) at the 0.5 μg L−1. The recoveries of Sc in the spiked environmental water samples ranged from 98.0% to 103% with 100 mL of water sample. The proposed method was validated using certified reference materials and applied to the determination of trace scandium in geological samples and environmental water samples with satisfactory results.

Ion imprinted polymer based potentiometric sensor for the trace determination of Cadmium (II) ions

A cadmium (II) ion selective electrode (ISE) based on an ion-imprinted polymer (IIP) as a novel ionophore has been prepared and studied. The ion-selective electrode (ISE) was prepared by dispersing cadmium (II) IIP particles in 2-nitrophenyloctyl ether as a plasticizer and then embedding them in a polyvinylchloride polymeric matrix. The Cd(II) ISE showed a nernstian response for cadmium (II) over the dynamic concentration range of 2.0×10−7–1.0×10−2molL−1, with a slope of 29.9mV per decade. The limit of detection was 1.0×10−7M. The proposed electrode revealed good selectivity over a wide variety of other cations including alkali, alkaline earth, heavy and transition metals. The accuracy of the proposed electrode was checked through the analysis of spiked water samples.

Synthesis and characterisation of nano structure lead (II) ion-imprinted polymer as a new sorbent for selective extraction and preconcentration of ultra trace amounts of lead ions from vegetables, rice, and fish samples

This paper describes the preparation of new Pb(II)-imprinted polymeric particles using 2-vinylpyridine as a functional monomer, ethylene glycol dimethacrylate as the cross-linker, 2,2′- azobisisobutyronitrile as the initiator, diphenylcarbazone as the ligand, acetonitril as the solvent, and Pb(NO3)2 as the template ion, through bulk polymerisation technique. The imprinted lead ions were removed from the polymeric matrix using 5mL of HCl (2mol.L−1) as the eluting solvent. The lead ion concentration was determined by flame atomic absorption spectrometry. Optimum pH for maximum sorption was obtained at 6.0. Sorption and desorption of Pb(II) ions on the IIP particles were quite fast and achieved fully over 5min.In the proposed method, the maximum sorbent capacity of the ion-imprinted polymer was calculated to be 75.4mgg−1. The preconcentration factor, relative standard deviation, and limit of detection of the method were found to be 245, 2.1%, and 0.42ngmL−1, respectively. The prepared ion-imprinted polymer particles have an increased selectivity toward Pb(II) ions over a range of competing metal ions with the same charge and similar ionic radius. This ion-imprinted polymer is an efficient solid phase for extraction and preconcentration of lead ions in complex matrixes. For proving that the proposed method is reliable, a wide range of food samples with different and complex matrixes was used.