Selective enrichment and separation of phosphotyrosine peptides by thermosensitive molecularly imprinted polymers

Novel thermosensitive molecularly imprinted polymers were successfully prepared using the epitope imprinting approach in the presence of the mimic template phenylphosphonic acid, the functional monomer vinylphosphonic acid‐Ti⁴⁺, the temperature‐sensitive monomer N‐isopropylacrylamide and the crosslinker N,N′‐methylenebisacrylamide. The ratio of the template/thermosensitive monomers/crosslinker was optimized, and when the ratio was 2:2:1, the prepared thermosensitive molecularly imprinted polymers had the highest imprinting factor. The synthetic thermosensitive molecularly imprinted polymers were characterized by Fourier transform infrared spectroscopy to reveal the combination and elution processes of the template. Then, the adsorption capacity and thermosensitivity was measured. When the temperature was 28°C, the imprinting factor was the highest. The selectivity and adsorption capacity of the thermosensitive molecularly imprinted polymers for phosphotyrosine peptides from a mixture of three tailor‐made peptides were measured by high‐performance liquid chromatography. The results showed that the thermosensitive molecularly imprinted polymers have good selectivity for phosphotyrosine peptides. Finally, the imprinted hydrogels were applied to specifically adsorb phosphotyrosine peptides from a sample mixture containing phosphotyrosine and a tryptic digest of β‐casein, which demonstrated high selectivity. After four rebinding cycles, 78.9% adsorption efficiency was still retained.     

Application of ion-imprinted polymer synthesized by precipitation polymerization as an efficient and selective sorbent for separation and pre-concentration of chromium ions from some real samples

In this study, a new Cr(III)-imprinted polymer (Cr(III)-IIP) is prepared from CrCl₃·6H₂O, methacrylic acid functional monomer, ethyleneglycoldimethacrylate cross-linking agent, 2,2?-azobisisobutyronitrile radical initiator and 2,2-(azanediylbis (ethane-2,1-diyl))bis(isoindoline-1,3-dione) ligand. To obtain the maximum adsorption capacity, the optimum condition was studied through pH, type and concentration of eluent, IIP weight, sample volume as well as the adsorption and desorption times. The Cr(III) ion content was determined via flame atomic absorption spectrometer. In optimum conditions, the adsorption capacity of the IIP for Cr(III) was obtained to be 74.65 mg g^?1, using 50 mg of IIP and the initial pH solution of 3.0. Both the adsorption and desorption times for quantitative analyses of Cr(III) ions were 15 and 5 min; respectively. After elution of the adsorbed ions by 3 mL of 4 mol L^?1 HNO₃ aqueous solution, the established IIP-based SPE procedure provides a reasonable pre-concentration factor of 100. The IIP-based pre-concentration method provides a low detection limit of 1.7 µg L^?1 with good repeatability (RSD?=?3.22%). Reusability studies confirmed that synthesis IIP is reusable and recoverable up to six cycles. According to the selectivity experiments, it was concluded that the prepared sorbent possesses more affinity toward Cr(III) ions than other ions such as Al³⁺, Pb²⁺, Cu²⁺, Mn²⁺, Fe²⁺, Zn²⁺, and Ni²⁺ ions. To evaluate the potential applicability of the proposed separation method, the pre-concentration and determination of trace amounts of Cr(III) were performed successfully in food samples with complex matrices, a bestial sample (i.e. cow liver) and an herbal product (i.e., broccoli) as real samples.     

Synthesis of multidentate functional monomer for ion imprinting

In this work, N,N,N‐tri(2‐carboxyethyl)‐3‐(2‐aminoethylamino)propyl‐trimethoxysilane was prepared as a multidentate functional monomer. The 3D model of the monomer coordinating with Cu²⁺ indicated that the monomer is able to provide five ligating atoms like ethylenediaminetetraacetic acid‐Cu²⁺ to complex with Cu²⁺. When Cu²⁺ was used as a template ion, the synthesis conditions of Cu²⁺‐imprinted polymers were optimized upon orthogonal design. It is interesting to find that Cu²⁺‐imprinted polymer offers a selectivity coefficient of 192.2 when the molar ratio of Cu²⁺ to monomer was exactly 1:1. That means there is no excess ligating atom in the ion‐imprinted polymer and therefore, the nonspecific adsorption could be avoided. Benefiting from the excellent selectivity of Cu²⁺‐imprinted polymer, even if the concentration of Zn²⁺ was 25 times that of Cu²⁺, Cu²⁺‐imprinted polymer still affords a high selectivity coefficient. Finally, the optimal synthesis conditions for Cu²⁺‐imprinted polymer, except the pH, were adopted to prepare Ni²⁺‐imprinted polymer, and Ni²⁺‐imprinted polymer also offered satisfying selectivity to Ni²⁺. That implies this multidentate monomer is adaptable in ion imprinting and, the optimal synthesis conditions of Cu²⁺‐imprinted polymer except pH are likely suitable for the imprinting of other ions besides Cu²⁺.     

Selective Solid‐phase Extraction of Cu2+ by a Novel Cu(II)‐imprinted Silica Gel

A new Cu(II)‐imprinted salen functionalized silica gel adsorbent was synthesized by surface imprinting technique and was employed as a selective solid phase extraction material for Cu²⁺ removal from aqueous solutions. The samples were characterized by FT‐IR, ¹HNMR, ¹³CNMR, CHNS and DTG techniques. The BET surface area of the silica gel was also determined. The adsorbent was then used for removal of Cu²⁺ from aqueous solutions under different experimental conditions. It was concluded that the synthesized imprinted silica gel had higher selectivity and capacity compared to the non‐imprinted silica gel and the maximal adsorption capacity of 67.3 and 56.5 mg.g^?1 was obtained respectively for ion‐imprinted and non‐imprinted adsorbents. The relative selectivity factor (β) of 50.32 and 31.94 was obtained respectively for Cu²⁺/Ni²⁺ and Cu²⁺/Zn²⁺ pairs. The dynamic adsorption capacity of the imprinted adsorbent was close to the static adsorption capacity due to the fast kinetic of adsorption. Furthermore, the ion‐imprinted adsorbent was recovered and repeatedly used and satisfactory adsorption capacity with acceptable precision was obtained. Each experiment was repeated at least for three times and the mean and the standard deviation for each measurement were calculated. The applicability of the method was examined for Zayandehrood water as real sample. Acceptabe standard deviation was obtained.     

Synthesis of a new ionic imprinted polymer for the extraction of uranium from seawater

The ionic imprinted polymer (IIP) of uranyl ion (UO₂ ²⁺) as the template was synthesized by the formation of binary complexes of UO₂ ²⁺ with 2,4-dioxopentan-3-yl methacrylate as functional monomer followed by thermal copolymerization with ethylene glycol dimethacrylate as cross-linking monomer in the presence of 2,2′-azobisisobutyronitrile as initiator and 1,4-dioxane as porogenic solvent. 50 mmol L^?1 HCl solution was used to leach out UO₂ ²⁺ ions from the IIP. Similarly, the control polymer was prepared under identical experimental conditions without using UO₂ ²⁺ ions. The above synthesized polymers were characterized by infra-red spectroscopy, thermo-gravimetric analysis and Barrett–Emmett–Teller surface area measurement. The maximum adsorption capacities of IIP and CP in (NH₄)₄[UO₂(CO₃)₃] solution were 15.3 and 11.2 mg U g^?1, respectively. The kinetics of adsorption followed a pseudo-second-order rate equation. The prepared IIP was successfully used to extract uranium from real seawater sample.     

An imprinted polymer for removal of Cd<Superscript>2+</Superscript> from water samples: Optimization of adsorption and recovery steps by experimental design

A new ion-imprinted polymer（ⅡP） was synthesized by copolymerization of 4-vinylpyridine（monomer）, ethyleneglycoldimethacrylate（cross-linker） and 2,2-azobis-isobutyronitrile（initiator） in the presence of Cd²⁺ and quinaldic acid（complexing agent）.It was found that the adsorption capacity of IIP and blank polymer were 45.0 and 6.2 mg g^-1, respectively.The relative selectivity coefficients of the imprinted polymer for different binary mixture were also calculated. Compared to non-imprinted polymer（NIP）,theⅡP had higher selectivity for Cd（Ⅱ）.TheⅡP was used as a sorbent for cadmium extraction from water samples by using a simple batch extraction procedure.The effect of different parameters on Cd²⁺ extraction and its recovery from theⅡP were evaluated and optimized by using experimental design methodology.The optimized adsorption/desorption procedure was applied for cadmium removal from the real water samples.The obtained recoveries proved that thisⅡP could be used for removal of trace cadmium ions from water samples.     

Preparing molecularly imprinted membranes by phase inversion to separate kaempferol

Molecularly imprinted membranes (MIMs) were studied to separate special target molecule – kaempferol, an important active pharmaceutical ingredient. The kaempferol MIM were prepared by the liquid–solid phase inversion method. The effects of polyphenylene sulfone, LiCl, and ZnCl₂ on membrane performance were studied, a high Flux MIM was prepared, then the kaempferol molecularly imprinted polymer membrane, non‐molecularly imprinted membrane, and non‐molecularly imprinted polymer membrane were prepared to investigate adsorption capacity. From adsorption isotherm curve, the maximum equilibrium adsorption quantity was 890 µg/g, and it was MIM. The MIM and molecularly imprinted polymer membrane give high selectivity towards kaempferol; the non‐molecularly imprinted membrane and non‐molecularly imprinted polymer membrane showed low adsorption quantity and selectivity. The reuse experiment of the MIM indicated that it has good reuse property. All the results showed binding sites were important in the separation process of MIMs. Copyright © 2016 John Wiley & Sons, Ltd.     

Rapid determination of antiviral medication ribavirin in different feedstuffs using a novel magnetic molecularly imprinted polymer coupled with high‐performance liquid chromatography

A novel magnetic molecularly imprinted polymer adsorbing material was successfully synthesized to detect ribavirin in animal feedstuff. Molecularly imprinted polymer was prepared through surface polymerization by using ribavirin as template molecule, methyl methacrylate, and γ‐methacryloxypropyl trimethoxy silane functionalized magnetic mesoporous silica as bifunctional monomers, and ethylene diglycidyl ether as crosslinking agent. The prepared magnetic molecularly imprinted polymer was characterized by scanning electron microscopy and infrared spectroscopy. Static and dynamic adsorption experiments and selective adsorption analysis were performed to evaluate the adsorption and selectivity of magnetic molecularly imprinted polymer. Different experiments were conducted to optimize the magnetic solid‐phase extraction conditions. Under optimal experimental conditions, a magnetic molecularly imprinted solid‐phase extraction coupled with high‐performance liquid chromatography method was successfully developed for ribavirin detection. The established method achieved a satisfactory linear range of 0.20–50 mg/L (R² > 0.99) and a low detection limit (0.081 mg/kg). An average recovery of 92–105% with relative standard deviation of <6.5% was obtained upon the application of the developed method to detect ribavirin in real feedstuff samples. Thus, established method can be used for the rapid and simple separation and detection of added ribavirin in feedstuff.     

Double-imprinted polymer based on cross-linked poly(vinylimidazole–trimethylolpropane trimethacrylate) in solid phase extraction for determination of lead from wastewater samples by UV–vis spectrophotometry

The monitoring of the heavy metal pollution in wastewater is increasingly becoming a crucial global issue since they tend to accumulate in food chains and can cause many biological abnormalities. In this work, it was developed a novel lead ion-imprinted polymer (IIP) using sodium dodecyl sulphate (SDS) as a second template to be used as adsorbent in solid phase extraction (SPE) for determination of lead from wastewater samples by UV–vis spectrophotometry. The polymer called IIP–SDS was synthesised by a double-imprinting process with lead (template) and SDS (template). IIP–SDS was characterised by infrared spectroscopy Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. IIP–SDS showed good recovery for lead (around 82.0%), while the IIP (only lead as template) was 72.2% and non-IIP was 44.9%. Thus, the double-imprinting process for the preconcentration of Pb²⁺ proved to be a more adequate methodology than IIP with a single template. The optimised parameters of sample preparation were washing solvent (2.0 mL of tetrahydrofuran), type and volume of eluent (5 mL of 1 mol L^?1 hydrochloric acid), sample amount (30 mL of water spiked with 10.0 µg mL^?1), amount of IIP–SDS (400 mg) and sample pH (pH = 4.5). Linearity ranged from 10 to 125 µg L^?1 with r > 0.992. The limit of detection and quantification were 6.3 and 10 µg L^?1, respectively. The precision (relative standard deviation, %) and accuracy (relative error, %) were lower than 15%. Finally, IIP–SDS may be an alternative and effective adsorbent for SPE procedures in monitoring of wastewater samples.     

A novel ion-imprinted nanocomposite for selective separation of Pb2+ ions

In this study, the ion-imprinting method has been integrated to develop a novel composite material for the selective separation of Pb²⁺ ions. Also, Pb²⁺ ion binding ability of the organosmectite based inorganic-organic composite incorporation of bicyclic C18 organic compound into smectite layers was conducted to draw a projection its potential use as a solid phase exchanger which is quite selective toward Pb²⁺ ions. The ion-imprinted nanocomposites were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), swelling tests, and elemental analyses. After that, maximum binding capacity, pH, and equilibrium binding time were also been optimized. In order to show the selectivity of the composite synthesized, non-imprinted composites were also synthesized in absence of Pb²⁺ ions during polymerization. In this step, Ni²⁺, Co²⁺, Al³⁺, Zn²⁺, and Cu²⁺ ions were used as competitors under batch adsorption conditions. The relative selectivity coefficients of imprinted composite were calculated as 28.5, 156.5, 69.3, 24.8 and 131.6 for Pb²⁺/Co²⁺, Pb²⁺/Cu²⁺, Pb²⁺/Al³⁺, Pb²⁺/Zn²⁺, Pb²⁺/Ni²⁺ binary solutions, respectively. Finally, reusability of the composites was evaluated to show its cost-efficiency by repeating adsorption-desorption experiments ten-times. The adsorption capacity of the imprinted composites did not change significantly whereas that of non-imprinted version reduced dramatically.     

Preparation and characterization of a novel molecularly imprinted polymer for the separation of glycyrrhizic acid

Molecularly imprinted polymers of glycyrrhizic acid were prepared by solution polymerization using glycyrrhizic acid as the template molecule, N‐vinypyrrolidone as functional monomer, N ,N‐methylene bisacrylamide as cross‐linker and ascorbic acid and hydrogen peroxide as initiators. Focused on the adsorption capacity and separation degree of the polymer to glycyrrhizic acid, the effects of the monomers, crosslinker and initiators were investigated and optimized. Finally, the structure of the polymer was characterized by using Fourier transform infrared spectroscopy and scanning electron microscopy. To obtain objective results, non‐imprinted molecular polymers prepared under the same conditions were also characterized. The adsorption quantity of the polymer was measured by high‐performance liquid chromatography. Under the optimum conditions, the maximum adsorption capacity of glycyrrhizic acid approached 15 mg/g, and the separation degree was as high as 2.5. The adsorption kinetics could be well described by a pseudo‐first‐order model, while the thermodynamics of the adsorption process could be described by the Langmuir model.     

Speciation,adsorption and determination of chromium(III) and chromium(VI) on a mesoporous surface imprinted polymer adsorbent by combining inductively coupled plasma atomic emission spectrometry and UV spectrophotometry

In the present study, a Cr(III)‐imprinted polymer (Cr(III)‐IIP) was prepared by an easy one‐step sol–gel reaction with a surface imprinting technique on the support of silica mesoporous material. A new SPE method for the speciation, separation, preconcentration, and determination of Cr(III) and Cr(VI) by inductively coupled plasma atomic emission spectrometry and UV on the mesoporous‐imprinted polymer adsorbent was developed. The structure of the imprinted polymer was characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, transmission electron microscopy, and nitrogen adsorption–desorption isotherms. The adsorption kinetics, thermodynamics behavior, and recognition ability toward Cr(III) on Cr(III)‐IIP and nonimprinted polymer were compared. The results showed that Cr(III)‐IIP had higher selectivity and nearly a two times larger Langmuir adsorption capacity (38.50 mg/g) than that of NIP. The proposed method has been successfully applied in the determination and speciation of chromium in natural water samples with satisfactory results.     

Synthesis of molecularly imprinted polymers using acrylamide‐β‐cyclodextrin as a cofunctional monomer for the specific capture of tea saponins from the defatted cake extract of Camellia oleifera

Molecularly imprinted polymers were synthesized using mixed tea saponins as a template and acrylamide‐β‐cyclodextrin as a cofunctional monomer for the specific binding and purification of tea saponins from the defatted cake extract of Camellia oleifera. The adsorption properties of the prepared polymers were systematically evaluated including adsorption kinetics, adsorption isotherms, and selective recognition characteristics. It showed that the adsorption kinetics followed the pseudo first‐order kinetic model (R² = 0.995) with an equilibrium time of 3 h, adsorption isotherm data fitted well with the Langmuir–Freundlich model (R² = 0.984) with an adsorption capacity of 14.23 mg/g. The relative selectivity coefficient (k´) in the presence of the analogues glycyrrhizic acid and glycyrrhetinic acid were 1.16 and 17.21, respectively. The performance of the molecularly imprinted polymers as solid‐phase extraction materials was investigated and the results indicated that using acrylamide‐β‐cyclodextrin as a cofunctional monomer improved both the adsorption capacity and active sites stability of the imprinted polymers. The solid‐phase extraction using the polymers as packing materials was subsequently applied for the separation of tea saponins in raw C. oleifera press extract, and targets were obtained with a purity reaching 89%.     

Novel adsorptive materials by adenosine 5ʹ‐triphosphate imprinted‐polymer over the surface of polystyrene nanospheres for selective separation of adenosine 5ʹ‐triphosphate biomarker from urine

In this study, we have developed a method to assess adenosine 5?‐triphosphate by adsorptive extraction using surface adenosine 5′‐triphosphate‐imprinted polymer over polystyrene nanoparticles (412 ± 16 nm) for selective recognition/separation from urine. Molecularly imprinted polymer was synthesized by emulsion copolymerization reaction using adenosine 5′‐triphosphate as a template, functional monomers (methacrylic acid, N‐isopropyl acrylamide, and dimethylamino ethylmethacrylate) and a crosslinker, methylenebisacrylamide. The binding capacities of imprinted and non‐imprinted polymers were measured using high‐performance liquid chromatography with UV detection with a detection limit of 1.6 ± 0.02 µM of adenosine 5′‐triphosphate in the urine. High binding affinity (Q_MIP, 42.65 µmol/g), and high selectivity and specificity to adenosine 5′‐triphosphate compared to other competitive nucleotides including adenosine 5?‐diphosphate, adenosine 5?‐monophosphate, and analogs such as adenosine, adenine, uridine, uric acid, and creatinine were observed. The imprinting efficiency of imprinted polymer is 2.11 for urine (Q_MIP, 100.3 µmol/g) and 2.51 for synthetic urine (Q_MIP, 48.5 µmol/g). The extraction protocol was successfully applied to the direct extraction of adenosine 5′‐triphosphate from spiked human urine indicating that this synthesized molecularly imprinted polymer allowed adenosine 5′‐triphosphate to be preconcentrated while simultaneously interfering compounds were removed from the matrix. These submicron imprinted polymers over nano polystyrene spheres have a potential in the pharmaceutical industries and clinical analysis applications.     

Theoretical and experimental studies of ion imprinted polymer for nitrate detection

Molecular imprinting is an approach to synthesize receptors with specific molecular recognition properties. A computational method was carried out to study interaction between template and monomer in prepolymerization mixture. The functional monomer and template complexes were optimized, at the minimum energy confirmation using Austin Model 1 semi empirical method within Restricted Hartree Fock formalism. The theoretical results showed that allylthiourea (functional monomer) has the largest interaction energy towards template (sodium nitrate) with the mole ratio of 4 : 1; functional monomer : template. The resulting polymers were characterized using Fourier Transform infrared spectroscopy, thermogravimetry analysis and field emission scanning electron microscopy. Rebinding experiments were carried out to evaluate binding capacity of the polymer. The adsorption data of ion imprinted polymer (IIP) were fitted with Langmuir-Freundlich isotherm model. Pseudo-second order kinetic model was used to describe the kinetic adsorption behavior of IIP. The experimental binding result showed good agreement with theoretical computation and the IIP was further used for nitrate ion detection. The results of membrane optimization indicated that the sensor, which composed of 30% polyvinylchloride, 60% nitrophenyl octyl ether as a plasticizer, 2% sodium tetraphenyl borate, and 10% IIP as ionophore exhibited an almost Nernstian slope with the limit of detection 3.9 × 10^-6 M. The fabricated sensor had shown good potential in nitrate detection with wide linear range, low limit of detection and found to have good selectivity towards nitrate ion over other anion.     

Via protoporphyrin to the synthesis of levofloxacin‐imprinted polymer

A new molecularly imprinted polymer (MIP) for levofloxacin was prepared by the combined use of methacrylic acid and protoporphyrin as functional monomers. The adsorption properties of resultant imprinted polymers were evaluated by equilibrium rebinding experiments. The highest binding capacity of levofloxacin achieved from the optimized imprinted polymer in acetonitrile was 246.26 µmol/g with an imprinting factor of 2.05. A ?uorescence quenching effect was observed when a protoporphyrin‐based imprinted polymer was incubated in the solutions of levofloxacin. The results indicated that the protoporphyrin‐based MIPs were able to create higher binding cavities for template compared with MIPs using only methacrylic acid as a functional monomer. It should be expected that the cooperative use of the protoporphyrin with supplemental different functional monomers may be an alternative to obtain MIP with the improvement of the selectivity. Copyright © 2010 John Wiley & Sons, Ltd.     

Preparation of thermosensitive,calix[4]arene incorporated P(NIPAM‐co‐HBCalix) hydrogel as a reusable adsorbent of nickel(II) ions

A calix‐conjugated thermo‐responsive hydrogel containing 15% tetra(5‐hexenyloxy)‐p‐tert‐butylcalix[4]arene (HBCalix), P(NIPAM‐co‐HBCalix), was used to remove nickel(II) ions from water. Both thermo‐sensitive properties and the Ni²⁺‐adsorption capabilities of the prepared P(NIPAM‐co‐HBCalix) hydrogels are investigated. Introduction of the monomer HBCalix considerably enhanced the adsorption of Ni²⁺ onto the hydrogel by chelation between hexenyloxy groups and metal ion. When HBCalix units capture Ni²⁺ and forms HBCalix/Ni²⁺ host–guest complexes, the lower critical solution temperature of the hydrogel shifts to a higher temperature due to both the repulsion between charged HBCali/Ni²⁺ groups and the osmotic pressure within the hydrogel. Adsorption studies were carried out by varying contact time, counter ion and initial concentration of Ni²⁺. The evaluation of adsorption properties showed that the hydrogel exhibited better correlation with Langmuir isotherm model. P(NIPAM‐co‐HBCalix) could be used repeatedly with little loss in adsorption capacity by simply changing the environmental temperature. This kind of ion‐recognition hydrogel is promising as a novel adsorption material for adsorption and separation of Ni²⁺ ions. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2401–2408     

Synthesis of a New Cu(II)-Ion Imprinted Polymer for Solid Phase Extraction and Preconcentration of Cu(II)

A new Cu(II)-ion imprinted polymer (IIP) has been synthesized by copolymerizing salicylic acid and formaldehyde as a monomer and crosslinker, respectively in the presence of Cu(II)-4-(2-pyridylazo) resorcinol complex. The imprinted Cu(II) ions were completely removed by leaching the IIP with 0.05 M EDTA. The maximum adsorption capacity for Cu(II) ions was 310 μg g^?1 at pH 6. The IIP was repeatedly used in adsorption–desorption experiments for seven times with recoveries ~95%. The relative selectivity factor (α _r) values of Cu(II)/Zn(II), Cu(II)/Cd(II), Cu(II)/Ni(II) and Cu(II)/Co(II) are 3.17, 2.90, 2.47 and 3.37, respectively. The detection limit corresponding to three times the standard deviation of the blank was found to be 3.0 μg L^?1. The developed IIP has also been tested for preconcentration and recovery of Cu(II) ions from water samples.     

Adsorption of carbaryl using molecularly imprinted microspheres prepared by precipitation polymerization

To obtain the desired specific adsorbents for carbaryl to enrichment, separation, and analysis of trace pesticide residues in environmental water, molecularly imprinted polymer (MIP) microspheres were prepared by precipitation polymerization using carbaryl, methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), azobisisobutyronitrile (AIBN), and acetonitrile as template, functional monomer, cross‐linker, initiator, and porogen, respectively. Molecular modeling software was used to compute rational interaction between the template molecule and function monomer. The adsorption properties of carbaryl in acetonitrile for imprinted microspheres were evaluated by equilibrium rebinding experiments. Scatchard plot analysis revealed that there was one class of binding sites populated in the imprinted polymer microspheres with dissociation constants of 3.3 × 10^?2 mol/l and an apparent maximum number of 1.95 µmol/g. The specificity of the imprinted microspheres was investigated by binding analysis using carbaryl and structurally related carbamate pesticides. The results indicated that the obtained imprinted microspheres showed a good selectivity for carbaryl. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis of a New Cu(II)-Ion Imprinted Polymer for Solid Phase Extraction and Preconcentration of Cu(II)

A new Cu(II)-ion imprinted polymer (IIP) has been synthesized by copolymerizing salicylic acid and formaldehyde as a monomer and crosslinker, respectively in the presence of Cu(II)-4-(2-pyridylazo) resorcinol complex. The imprinted Cu(II) ions were completely removed by leaching the IIP with 0.05 M EDTA. The maximum adsorption capacity for Cu(II) ions was 310 μg g⁻¹ at pH 6. The IIP was repeatedly used in adsorption–desorption experiments for seven times with recoveries ~95%. The relative selectivity factor (α _r) values of Cu(II)/Zn(II), Cu(II)/Cd(II), Cu(II)/Ni(II) and Cu(II)/Co(II) are 3.17, 2.90, 2.47 and 3.37, respectively. The detection limit corresponding to three times the standard deviation of the blank was found to be 3.0 μg L⁻¹. The developed IIP has also been tested for preconcentration and recovery of Cu(II) ions from water samples.