Molecularly Imprinted Polymer Solid-phase Extraction Research Articles

A Semi-Automated Molecularly Imprinted Polymer Solid-Phase Extraction Method for Catechin Analysis from Jaboticaba (Plinia sp.) Peel Extract Samples by UHPLC-DAD

Jaboticaba (Plinia sp.), a nutritionally significant Brazilian fruit, is rich in phenolic compounds, such as catechin, known for its biological and pharmaceutical properties. Extracting and studying these compounds is an economic and environmental strategy to fully explore the great potential that these chemical compounds have. Therefore, this study focuses on developing a semi-automated solid-phase extraction method using molecularly imprinted polymer for catechin analysis in jaboticaba peel extracts, coupled with an ultra-high-performance liquid chromatography with a diode array detector. The reported polymer demonstrated superior extractor capacity compared to the non-imprinted polymer. Different extraction parameters were optimized, and the method exhibited a linear range of 10 to 100 µg mL-1 for catechin. The obtained precision with the coefficient of variation was below 7.3%, and the limits of quantification and detection were 12.4 and 4.1 µg mL-1 , respectively. The developed sorbent maintained analytical performance through approximately 40 injections. Results suggest that the reported method could efficiently extract catechin from jaboticaba peels in less than 10 min, providing a promising tool for the rapid investigation of natural products. This selective and sustainable approach demonstrated here contributes to the economic and environmental aspects of catechin extraction and analysis in jaboticaba fruit.

Molecularly Imprinted Polymer Solid-Phase Extraction (MISPE) for the Determination of Dinitro-ortho-cresol (DNOC) and Its Risk Assessment in Tomatoes

In this study, the molecularly imprinted polymer solid-phase extraction (MISPE) method for the determination of dinitro-ortho-cresol (DNOC) before HPLC (High-performance liquid chromatography) analysis was conducted. This study aims to analyze the sorption behavior and the potential use of molecularly imprinted polymers (MIP) for DNOC extraction. MIP was prepared using a combination of methacrylic acid as the functional monomer; ethylene glycol dimethacrylate as the crosslinker, benzoyl peroxide as the initiator, and acetonitrile as the porogen. The results showed that the optimum adsorption of the material was achieved at pH 5 for a contact time of 30 min with an adsorption capacity of 137 mg/g. The ideal eluent for desorption was a mixture of methanol and acetic acid with a ratio of 3:1. The calculations showed that the adsorption process followed the Sips adsorption isotherm model (n = 0.967), which indicated adsorption on both homogeneous and monolayer surfaces. Reusability studies that were conducted via three consecutive adsorption-desorption cycles resulted in recovery values of 109.4%, 108.8%, and 101.1%. The concentration of DNOC obtained from tomato samples was 0.65 mg/kg with a recovery rate of 87.17%; this was within the tolerable range between 80% and 110%. Based on the high recovery and low LoQ, this method can be used to quantify DNOC quickly.

Bisphenol A in edible tissues of rams exposed to repeated low-level dietary dose by high-performance liquid chromatography with fluorescence detection

The presented work deals with levels and distribution of bisphenol A (BPA) in the edible tissues of a large food-producing animal species. An experimental animal study included 14 young Istrian pramenka rams (Ovis aries), of which seven were exposed for 64 days to a low dietary dose of BPA at 25 µg/kg b.w./day, and seven served as a control group. Residue analysis of both aglycone and total BPA was performed in the muscle tissue, liver, kidney and fat tissue of the individual animals by means of enzymatic deconjugation (for total BPA), organic solvent extraction, molecularly imprinted polymer solid-phase extraction (MISPE) clean-up and high-performance liquid chromatography with fluorescence detection (HPLC-FLU). The analysis was optimized and validated for aglycone BPA in the fat tissue and for the total BPA in all tissues investigated. Edible tissues of the control group of rams generally remained BPA-free, while there were concentration differences between the control and treated groups for liver and kidney post last administration. The human health risk resulting from this study was assessed by the estimated dietary exposure in adults, which was < 0.1% related to the valid European Union Tolerable Daily Intake (TDI) value of 4 µg/kg b.w./day. However, it would be 58-fold higher than the newly proposed TDI value of 0.04 ng/kg b.w./day.

An Update on the Use of Molecularly Imprinted Polymers in Beta-Blocker Drug Analysis as a Selective Separation Method in Biological and Environmental Analysis.

Beta-blockers are antihypertensive drugs and can be abused by athletes in some sport competitions; it is therefore necessary to monitor beta-blocker levels in biological samples. In addition, beta-blocker levels in environmental samples need to be monitored to determine whether there are contaminants from the activities of the pharmaceutical industry. Several extraction methods have been developed to separate beta-blocker drugs in a sample, one of which is molecularly imprinted polymer solid-phase extraction (MIP-SPE). MIPs have some advantages, including good selectivity, high affinity, ease of synthesis, and low cost. This review provides an overview of the polymerization methods for synthesizing MIPs of beta-blocker groups. The methods that are still widely used to synthesize MIPs for beta-blockers are the bulk polymerization method and the precipitation polymerization method. MIPs for beta-blockers still need further development, especially since many types of beta-blockers have not been used as templates in the MIP synthesis process and modification of the MIP sorbent is required, to obtain high throughput analysis.

Nano-sized magnetic core-shell and bulk molecularly imprinted polymers for selective extraction of amiodarone from human plasma

Bulk and magnetic core-shell Molecularly Imprinted Polymers (MMIPs) have been introduced and compared to extract and determine amiodarone from a complex matrix, i.e., plasma, due to the importance of Therapeutic Drug Monitoring (TDM). Polymer synthesis was confirmed by FTIR, AFM, TGA, DLS, VSM, TEM, and the adsorption studies such as capacity, isothermal models, selectivity, and regeneration were performed to evaluate and compare polymer efficiency in extraction and separation of amiodarone from sample solutions and human plasma. Both nano-sized and bulk polymers successfully extracted the target molecule at the low therapeutic ranges and the overdose concentrations (recoveries of 98.38%–102.70%). The maximum adsorption capacity of the MMIPs was 42.5 μg/mg compared with 2.6 μg/mg for bulk polymers. The imprinting factors of the polymers were 15.12 and 6.84 for MMIPs and bulk, respectively. MMIPs and bulk polymers presented 4.68 and 1.66 selectivity factors, respectively, towards amiodarone compared with lidocaine. LOD, LOQ, and enrichment factor in human plasma were 0.09, 0.28 μg mL−1, and 10 respectively. Recoveries of therapeutic concentration from plasma were 91.38 and 97.33% for bulk and MMIPs, respectively. MMIPs as an adsorbent in amiodarone extraction from plasma offered reduced necessary sample amount, less adsorbent consumption, reduced pretreatment time, and reduced elution solvent waste while yielding higher extraction recovery and more specificity for the target compared with the bulk polymer. Bulk polymers have a more straightforward synthesis procedure due to fewer synthesis steps and fewer variables, and Molecularly Imprinted Polymer Solid-phase Extraction (MIP-SPE) has already been introduced commercially. MMIPs prevail on a small scale, and in the context of a simple extraction, separation, or concentration in large-scale bioanalysis, efforts towards optimization and development of MMIPs can unearth tremendous opportunities for green chemistry principles.

Development of isotope dilution-liquid chromatography/tandem mass spectrometry as a candidate reference method for the accurate determination of patulin in apple products.

The incidence of patulin (PAT) in fruit products is a worldwide concern due to its acute and chronic toxic effects. Therefore, accurate and reliable PAT measurements are important for preventing consumer health risks. Our previous method, which was based on a common technique that uses ethyl acetate extraction and liquid chromatography-tandem mass spectrometry with isotope dilution (ID-LC-MS/MS), has shown great performance for the determination of PAT in apple products. However, prolonged extraction times and multistep clean-up processes were required to sufficiently eliminate the matrix interferences. Herein, a feasible alternative ID-LC-MS/MS method was successfully established, employing simplified and reliable sample preparation steps. The clean-up process was performed using molecularly imprinted polymer-solid-phase extraction (MIP-SPE) cartridges, which eliminated matrix interferences and facilitated the trace quantification. While the previous method used a multimode LC column for the retention of polar patulin, the current method used a UPLC HSS T3 column, which further improved the peak sharpness and reduced the run time. The method was validated by measuring fortified samples in the concentration range of 5‒100µg/kg. The accuracy varied between 97.8 and 102.0%, with relative standard deviation for interday and intraday precision being below 3%. The measurement uncertainty was lower than 4% (at a 95% level of confidence). Therefore, this method demonstrated adequate metrological quality with greatly enhanced performance over various reported methods. Additional key benefits of this method are easy manipulation, short preparation time, and lower consumption of hazardous solvents. Finally, the method was successfully applied to commercially available apple-based products.

Selective extraction of zolpidem from plasma using molecularly imprinted polymer followed by high performance liquid chromatography

This study aimed to develop a method for determination of zolpidem as a widely used hypotonic in human plasma using a common analysis method/detector. A novel molecularly imprinted polymer-solid phase extraction (MIP-SPE) method was used for extraction of zolpidem and concentrating it in the sample to be analyzed. A number of MIPs were prepared and MIP with highest extraction efficiency was characterized by FTIR spectroscopy, scanning electron microscopy and zeta potential analyzer. Extraction time and pH of zolpidem aqueous solution were optimized and capacity of MIP for adsorbing zolpidem was determined. A HPLC-fluorescence detector method was validated and used for analysis of zolpidem samples extracted from plasma. The method was linear in the range of 10–100 ng/ml (R2 = 0.9992) with RSD values in the range of 0.45–2.86% and LOD and LOQ of 0.34 and 1.04 ng/ml, respectively. Extraction and analysis of zolpidem from spiked human plasma samples determined zolpidem with more than 90% recovery. Finally, developed method was used to construct the plasma concentration profile of zolpidem for a volunteer person after taking single oral dose of zolpidem.

Development of a sensitive method for the analysis of four phthalates in tea samples: Tea bag contribution to the total amount in tea infusion

ABSTRACT A sensitive, precise and selective method for the analysis of butyl benzyl phthalate (BBP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and dimethyl phthalate (DMP) in tea samples has been applied. Molecularly Imprinted Polymer-Solid Phase Extraction (MIP-SPE) has been used for the separation and preconcentration of these compounds. Phthalates extracted by SPE were analysed by high-performance liquid chromatography-electrospray ionisation-mass spectrometry (HPLC-ESI-MS). The method was sensitive (LOD < 2 µg L−1), precise (RSD <10%) and accurate with recovery percentages ranging from 84% to 97%. Finally, the developed method was applied for the analysis of these phthalates in several tea samples marketed in bags. Migration studies were also performed to evaluate the concentration of phthalates released from the bags into the infusions, and teabag filters were analysed by Fourier-transform infrared spectroscopy. The migration study shows that tea filter bags contribute to the total phthalates concentration in tea infusion, and this contribution varies between 1.8 to 93.5 % of the total phthalates’ concentrations. Tea filter bags release higher DBP than BBP, DMP, and DEP.

Quantification of ultratrace levels of fluoroquinolones in wastewater by molecularly imprinted solid phase extraction and liquid chromatography triple quadrupole mass

Abstract In this work a selective and sensitive analytical method for simultaneous determination of 11 fluoroquinolones antibiotics in water was developed by ultra-high performance liquid chromatography coupled to mass spectrometry (U-HPLC/MS–MS). Molecularly imprinted polymers solid-phase extraction (MIP-SPE) was used for the enrichment. The recoveries of samples in matrix was more than 75%, RSD value was less than 15%. The detection limit of fluoroquinolones is ng L − 1 . Norfloxacin, ofloxacin and enrofloxacin were determined in the sludge, difloxacin and sarafloxacin were found in both effluent and sludge. Antibiotics used in animal husbandry and aquaculture may have a significant influence on the WWTP influent.

Improving performance of molecularly imprinted polymers prepared with template of low purity utilizing the strategy of macromolecular crowding

The topic in the present paper is to prepare molecularly imprinted polymer (MIP) using the template molecule with low purity. For the first time, a surrounding of macromolecular crowding was established to promote the formation of the complex of the template with functional monomer efficiently thus highly pure template molecule was unnecessary. In this study, the MIP monolith was synthesized using low purity lactucopicrin as template in place of highly pure one, and polystyrene was used as macromolecular crowding agent. 4-Vinylpyridine and ethyleneglycol dimethacrylate were used as functional monomer and crosslinker, respectively. Polymerization parameters, including the ratio of functional monomer/template, various template concentrations, and PS concentration on the affinity of the resulting MIP were systematically investigated. For the lactucopicrin MIP made with the purity of lactucopicrin of 92%, the imprinting factor can be up to 2.2. The resulting MIP was filled in solid phase extraction (SPE) cartridge to purify lactucopicrin from the crude extract of Cichorium glandulosum Boiss. et Huet. After two cycles of MIP SPE for the crude extract, the highest recovery and purity of lactucopicrin was 64.8% and 97.8%, respectively. The results indicated that the use of macromolecular crowding agent is an effective method for improving the performance of the MIP prepared with the template of low purity, particularly valuable to the cases in which the highly pure target molecule is hard to be obtained.

Pre-concentration of rosuvastatin using solid-phase extraction in a molecularly imprinted polymer and analytical application in water supply

In this work, it is shown the development and validation of innovative analytical methodology based on solid-phase extraction (SPE) with molecularly imprinted polymers (MIP) as a sorbent associated to UV-Vis spectroscopy to isolate and quantify, respectively, rosuvastatin (RSV) in water samples. For this purpose, porogenic solvent in MIP synthesis and SPE extraction parameters for MIP and non-imprinted polymers (NIP) were evaluated univariately for comparison purposes. The sorptive capacity and characterization studies by infrared spectroscopy and atomic force microscopy showed difference between MIP and NIP. The selectivity study of the MIP-RSV against other statins (simvastatin and atorvastatin) showed that the synthesized MIP can also be applied as a solid phase for isolation and quantitative pre-concentration of RSV and atorvastatin. The conjugation of SPE and UV-Vis spectroscopy in the determination of RSV in aqueous matrices led to large factor of pre-concentration (125 times), limit of detection (LOD) of 3μgL-1, limit of quantification (LOQ) of 10μgL-1, precision of 2.87% (n = 10), and accuracy of 83.1% (n = 4).

Miniaturized imprinted solid phase extraction to the selective analysis of Coenzyme Q10 in urine

Coenzyme Q10 (CoQ10) is an important cofactor in the mitochondrial respiratory chain and a potent endogenous antioxidant. CoQ10 deficiency is currently associated with numerous diseases like mitochondrial and neurodegenerative pathologies, in which the earliest diagnosis and treatment with CoQ10 supplementation becomes paramount for patient's treatment. Consequently, the determination of CoQ10 levels in different biological matrices positions as a fundamental tool. Urine is an attractive and non-invasive alternative source to tissue, blood or other biofluids for CoQ10 analysis. However, it poses an analytical challenge, as it generally requires a complex sample preparation, with multiple steps. In this work we developed and validated a molecularly imprinted polymer solid phase extraction (MIP-SPE) followed by a HPLC-MS/MS method for the analysis of CoQ10 in urine. The MIP-SPE method developed is simple and fast compared to previously traditional reported methods, with reduced processing time, improved sample cleaning and excellent recovery values, along with its inherent high selectivity. The developed chromatographic method was validated according to FDA guidelines, and demonstrated to be suitable for the analysis of CoQ10 in urine samples with LOQ and LOD values of 0.6 ng/mL and 0.2 ng/mL of CoQ10 in urine respectively. Recovery values at three concentration levels were higher than 90.0%.The proposed method is amenable to be applied in pediatric patients due to the low sample requirement and useful for diagnosis and post-treatment control.

Molecularly imprinted solid phase extraction coupled with gas chromatography-mass spectrometry for determination of N-Nitrosodiphenylamine in water samples

In this study, the molecularly imprinted polymers (MIPs) with high specific surface area and extraction efficiency of N-Nitrosodiphenylamine (NDPhA) were successfully prepared and a highly sensitive and selective method was developed for determination of NDPhA in water samples using MIPs solid-phase extraction (SPE) coupled with gas chromatography mass spectrometry (GC-MS) detection. The MIPs were successfully prepared using the method of precipitation polymerization and using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and N, N-Diphenylformamide as the template molecule. The newly synthesized MIPs were characterized and used as SPE sorbents. Under the optimized conditions, the average recoveries of NDPhA spiked in ultrapure water were higher than 94% ± 2.9% at three different concentrations and the limit of detection and limit of quantitation were 0.8 ng L−1 and 2.4 ng L−1, respectively. Moreover, the high selectivity of MIPs was attained and the satisfactory recoveries of NDPhA which were spiked in to real samples were achieved in the range of 92–107% with relative standard deviations (RSDs) within 0.3–7.9%. The low levels of NDPhA were detected in the two of twelve wastewater samples with concentrations of 5.6 ng L−1 and 3.6 ng L−1 with RSDs of 5.6% and 2.8%, respectively. The developed MIP-SPE method was proved to be practically feasible for selective extraction and enrichment of NDPhA in real water samples.

Determination of 14 aminoglycosides by LC-MS/MS using molecularly imprinted polymer solid phase extraction for clean-up

ABSTRACTAn LC-MS/MS method for screening 14 aminoglycosides in foodstuffs of animal origin is presented. Its scope includes raw materials and processed ingredients but also finished products composed of milk, meat, fish, egg or fat. Aminoglycosides are extracted in an acidic aqueous solution, which is first recovered after centrifugation, then diluted with a basic buffer and finally purified by molecularly imprinted polymer-solid phase extraction (MIP-SPE). Analytes are detected within 8 min by ion-pair reversed phase LC-MS/MS. Due to the large range of foodstuffs involved, the variability of matrix effects led to significant MS signal variations. This was circumvented by systematically extracting each sample twice, i.e. ‘unspiked’ and ‘spiked’ at the screening target concentration of 50 µg kg−1. The method was validated according to the European Community Reference Laboratories Residues Guidelines giving false-negative and false-positive rates ≤3% for all compounds. Ruggedness of the method was further demonstrated in quality control operations by a second laboratory. The 14 aminoglycosides in water-based standard solutions were stable for up to 6 months when stored at either −80°C, −20°C or at 4°C storage temperatures.

Comparison of Bulk and Precipitation Polymerization Method of Synthesis Molecular Imprinted Solid Phase Extraction for Atenolol using Methacrylic Acid

Objective: Atenolol is one of beta-blocker are prohibited as doping based on World Anti-Doping Agency (WADA). The purpose of this study was to the synthesis of molecular imprinted polymer (MIP) for extraction of atenolol from the sample. Method: This research compared the two of the method, bulk and precipitation polymerization. The MIP was successfully prepared from methacrylic acid as a functional monomer, ethyleneglycoldimethacrylate as a crosslinker, benzoyl peroxide as an initiator, butanol as a porogenic solvent with atenolol as a template molecule. Result: The result showed that the bulk polymerization method produces sorbents that have good adsorption capacity and small particle compare to the precipitation polymerization. Both methods were selective for atenolol. Conclusion: Generally, the MIP solid phase extraction is an alternative method for extraction atenolol from the sample. Key words: Atenolol, Molecular Imprinted Polymer, Solid Phase Extraction.

Filter Plate–Based Screening of MIP SPE Materials for Capture of the Biomarker Pro-Gastrin-Releasing Peptide

Affinity-based solid-phase extraction (SPE) is an attractive low-cost sample preparation strategy for biomarker analysis. Molecularly imprinted polymers (MIPs) as affinity sorbents offer unique opportunities for affinity SPE, due to their low manufacturing cost and high robustness. A limitation is the prediction of their affinity; therefore, screening of analyte recovery and specificity within a large range of SPE conditions is important in order to ensure high-sensitivity detection and assay reproducibility. Here, a µ-SPE method for screening of the MIP-SPE materials using a commercial 384-well filter plate is presented. The method allows for rapid and automated screening using 10–30 µL of packed SPE sorbent per well and sample volumes in the range of 10–70 µL. This enables screening of many different SPE sorbents while simultaneously identifying optimal SPE conditions. In addition, the 384-well format also facilitates detection with a multitude of analytical platforms. Performance of the µ-MIP-SPE method was investigated using a series of MIPs designed to capture pro-gastrin-releasing peptide (ProGRP). Fractions coming from sample load, cartridge wash, and elution were collected and analyzed using mass spectrometry (MS). The top-performing MIPs were identified, together with proper SPE conditions.

Simultaneous preconcentration and determination of malachite green and fuchsine dyes in seafood and environmental water samples using nano-alumina-based molecular imprinted polymer solid-phase extraction

ABSTRACTMolecular imprinted polymer for determination of malachite green (MG) and fuchsine basic (FU) dyes by spectrophotometry has been used, to develop a novel simultaneous extraction and preconcentration method. Molecularly imprinted layer-coated nano-alumina (MIP@Nano-Al2O3) as adsorbent was prepared by surface molecular imprinting technique, and characterised by FTIR spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis (EDAX) and thermogravimetric analysis (TGA). The method is based on simultaneous extraction of MG and FU dyes from aqueous solution by using molecularly imprinted polymer and measuring the absorbance at 617 and 546 nm for MG and FU, respectively. Parameters which affect the extraction efficiency such as pH, volume of eluent and amount of adsorbent were investigated and optimised. Linear calibration curves were obtained in the range of 2–750 ng mL−1 for MG and 1–240 ng mL−1 for FU under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.655 and 0.245 ng mL−1 (n = 10) for MG and FU, respectively. The relative standard deviation (RSD) for 100 ng mL−1 of MG and FU was 2.35 and 3.06% (n = 7), respectively. The method was applied to the simultaneous determination of the dyes in different seafood and environmental water samples.

Molecularly Imprinted Solid-Phase Extraction: Extraction of Traditional Chinese Medicine Active Ingredients

Molecular imprinting technology (MIT) is a developing technique with high recognition which is just like the recognition between enzymes and antibodies in the organism. Molecularly imprinted polymers (MIPs), synthetic materials obtained using the imprinting technology, have played a huge advantage and been used in many fields. Especially, MIPs have been applied to the extraction and separation of analytes as the selective adsorbent of solid-phase extraction (SPE), which is known as molecularly imprinted polymer solid-phase extraction (MISPE) in recent years. In the present review, the methodology of MIPs preparation and evaluation are explained. Moreover, recent great developments of SPE and MISPE are discussed, and the potential application of MISPE in extraction of traditional Chinese medicine (TCM) active ingredients are also presented briefly.

Molecularly imprinted polymers for solid phase extraction of orghanophosphorus pesticides

Molecularly imprinted polymer-solid phase extraction (MIP-SPE) adsorbent was prepared for the analysis of selected organophosphorus pesticides(OPPs) in environmental sample. In this work, the influence of process parameters on the preparation of imprinted polymer is presented. In theprocedure of polymerization, molecularly imprinted bulk polymer was prepared using quinalphos and methacrylic acid (MAA) as template molecule and functional monomer, respectively. The influence of the following parameters on recognition properties was investigated namely, types of crosslinker (ethylene glycol dimethacrylate (EGDMA) or divinylbenzene (DVB)) and porogenic solvents (acetonitrile, dichloromethane, toluene, chloroform). Molar ratio of template:functional monomer:cross linker was fixed at 1:4:20. Soxhlet extraction method was conducted to remove the imprint molecule in order to create the recognition sites. A blank/non-imprinted polymer (NIP) was produced simultaneously using identical procedure except in the absence of template molecule.

Preparation and Properties of Formaldehyde Molecularly Imprinted Polymer and Its Application in Detectiong Formaldehyde in Aquatic Product

Molecularly imprinted polymer( MIP) was prepared by optimized method using formaldehyde as template molecule,α-methacrylic acid as functional monomer,ethylene glycol dimethacrylate as crosslinking agent in chloroform. The imprinted polymer has the best selective adsorption capacity when the molar ratio of template molecular,functional monomer,crosslinking agent is 1∶ 2∶ 20,the prepolymerization time is 4 h,and the polymerization time is 8 h. When the concentration of formaldehyde solution is 2 mmol / L,the adsorption capacity of MIP reaches 12. 40 × 10-2mmol / g. The analysis of squid water sample indicated formaldehyde concentration was 5. 92 mg / Kg. At the same time,formaldehyde was not detected when the test sample was diluted 100 times, while after enriched by MIP solid-phase extraction( MIPSE) the concentration of formaldehyde was 5. 76 mg / Kg. Formaldehyde MIP has high-efficiency in enriching low concentration formaldehyde for sample preparation,and there is no significant difference in the testing results.