Selective 17‐β‐estradiol molecular imprinting

An efficient novel method for the synthesis of a covalent molecularly imprinted polymer (MIP) highly specific to β‐estradiol have been developed. MIP prepared by both covalent and non covalent techniques, demonstrated high selectivity toward β‐estradiol. MIPs were synthesized by radical polymerization of 17‐β‐estradiol 4‐vinyl‐benzene carboxyl or sulfonyl esters used as covalent functional monomers, methacrylic acid as noncovalent functional monomer, ethylene glycol dimethacrylate as crosslinking agent, and acetonitrile as swelling and porogenic component. Almost 35% (w/w) of 17‐β‐estradiol was successfully removed from the polymer network by basic hydrolysis. The binding ability of MIP was 10.73 μg/mg MIP following removal of 17‐β‐estradiol in the 2 mg/mL β‐estradiol solution. Selective rebinding of β‐estradiol toward MIP was tested in the presence of competitive binders including estrone, 19‐nortestosterone, epiandrosterone, and cholesterol. Estrone having closest similar chemical structure to β‐estradiol exhibited only 0.6 μg/mg MIP competitive binding, being exposed to equivalent concentrations. Moreover, other competitive steroids demonstrated negligible affinity toward MIP indicating high selectivity of novel MIP system toward β‐estradiol. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5534–5542, 2009     

New sulfonate composite functionalized with multiwalled carbon nanotubes with cryogel solid‐phase extraction sorbent for the determination of β‐agonists in animal feeds

A new mixed‐mode cation‐exchange sulfonate composite functionalized with multiwalled carbon nanotubes with polyvinyl alcohol cryogel was fabricated and used for the first time as a solid‐phase extraction sorbent for the determination of β‐agonists in animal feeds. Feed samples were extracted with 0.20 M phosphoric acid and methanol (1:4, v/v) using ultrasonication, cleaned‐up using the developed sorbent to which the β‐agonists bound then finally eluted with 5.0% ammonia in methanol and analyzed by high‐performance liquid chromatography. Various parameters that affected the extraction efficiency were optimized. Under the optimal conditions, the developed sorbent strongly interacted with β‐agonists by cationic exchange and hydrophobic and hydrophilic interactions, that provided a high extraction efficiency in the range of 92.8 ± 3.7–104.4 ± 2.3% over a range of 0.04–2.0 mg/kg for salbutamol and ractopamine, and 0.40–8.0 mg/kg for clenbuterol. The relative standard deviations were less than 6.0%. The developed method was successfully applied for the determination of β‐agonists in various types of animal feed and effectively reduced any matrix interference.     

Computational design and fabrication of core–shell magnetic molecularly imprinted polymer for dispersive micro‐solid‐phase extraction coupled with high‐performance liquid chromatography for the determination of rhodamine 6G

A novel core–shell magnetic nano‐adsorbent with surface molecularly imprinted polymer coating was fabricated and then applied to dispersive micro‐solid‐phase extraction followed by determination of rhodamine 6G using high‐performance liquid chromatography. The molecularly imprinted polymer coating was prepared by copolymerization of dopamine and m‐aminophenylboronic acid (functional monomers), in the presence of rhodamine 6G (template). The selection of the suitable functional monomers was based on the interaction between different monomers and the template using the density functional theory. The ratios of the monomers to template were further optimized by an OA₉ (3⁴) orthogonal array design. The binding performances of the adsorbent were evaluated by static, kinetic, and selective adsorption experiments. The results reveal that the adsorbent possesses remarkable affinity and binding specificity for rhodamine 6G because of the enhanced Lewis acid‐base interaction between the B(Ш) embedded in the imprinted cavities and the template. The nano‐adsorbent was successfully applied to dispersive micro‐solid‐phase extraction coupled to high‐performance liquid chromatography for the trace determination of rhodamine 6G in samples with a detection limit of 2.7 nmol/L. Spiked recoveries ranged from 93.0–99.1, 89.5–92.7, and 86.9–105% in river water, matrimony vine and paprika samples, respectively, with relative standard deviations of less than 4.3%.     

Monodisperse restricted access material with molecularly imprinted surface for selective solid‐phase extraction of 17β‐estradiol from milk

In this study, novel monodisperse restricted access media‐molecularly imprinted polymers were successfully prepared by surface initiated reversible addition‐fragmentation chain transfer polymerization using monodisperse crosslinked poly (glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) microspheres as the carrier and acryloyl chloride‐modified β‐cyclodextrin as the hydrophilic functional monomer. The surface morphology, protein exclusion, and adsorption properties of the molecularly imprinted polymers were investigated. The results show that the material has excellent monodispersity and hydrophilicity, and simultaneously exhibit high adsorption capacity, fast binding kinetics, high selectivity, and significant thermal stability. The molecularly imprinted polymers as dispersive solid‐phase extraction adsorbent combined with reversed‐phase high‐performance liquid chromatography was used to selectively enrich, separate, and analyze trace 17β‐estradiol in milk samples. The recovery of 17β‐estradiol is 88–95% with relative standard deviation of <4%, and the limits of detection and quantification of this method are 2.08 and 9.29 µg/L, respectively. The novel restricted access media‐molecularly imprinted polymer adsorbents provide an effective method for the selective extraction and detection of 17β‐estradiol directly from complex samples.     

Development of a Sensitive Method for the Determination of 4‐(Methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol in Human Urine Using Solid‐phase Extraction Combined with Ultrasound‐assisted Dispersive Liquid–liquid Microextraction and LC‐MS/MS Detection

An efficient and sensitive analytical method based on molecularly imprinted solid‐phase extraction (MISPE) and reverse‐phase ultrasound‐assisted dispersive liquid–liquid microextraction (USA‐DLLME) coupled with LC–MS/MS detection was developed and validated for the analysis of urinary 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL), a tobacco‐specific nitrosamine metabolite. The extraction performances of NNAL on three different solid‐phase extraction (SPE) sorbents including the hydrophilic‐lipophilic balanced sorbent HLB, the mixed mode cationic MCX sorbent and the molecularly imprinted polymers (MIP) sorbent were evaluated. Experimental results showed that the analyte was well retained with the highest extraction recovery and the optimum purification effect on MIP. Under the optimized conditions of MIP and USA‐DLLME, an enrichment factor of 23 was obtained. Good linearity relationship was obtained in the range of 5‐1200 pg/mL with a correlation coefficient of 0.9953. The limit of detection (LOD) was 0.35 pg/mL. The recoveries at three spiked levels ranged between 88.5% and 93.7%. Intra‐ and inter‐day relative standard deviations varied from 3.6% to 7.4% and from 5.4% to 9.7%, respectively. The developed method combing the advantages of MISPE and DLLME significantly improves the purification and enrichment of the analyte and can be used as an effective approach for the determination of ultra‐trace NNAL in complex biological matrices.     

Evaluation of matrix solid‐phase dispersion extraction for 11 β‐agonists in swine feed by liquid chromatography with electrospray ionization tandem mass spectrometry

A sensitive liquid chromatography with tandem mass spectrometry method was developed for the determination of 11 β‐agonists (clenbuterol, salbutamol, ractopamine, terbutaline, fenoterol, cimaterol, isoxsuprine, mabuterol, mapenterol, clenproperol, and tulobuterol) in swine feed. This rapid, simple, and effective extraction method was based on matrix solid‐phase dispersion. The limit of quantification of clenbuterol, cimaterol, mabuterol, salbutamol, terbutaline, mapenterol, clenproperol, and tulobuterol was 1 μg/kg and that of ractopamine, fenoterol, and isoxsuprine was 2 μg/kg. The recoveries of β‐agonists spiked in swine feeds at a concentration range of 1–8 μg/kg were >83.1% with relative standard deviations <9.3%. This rapid and reliable method can be used to efficiently separate, characterize, and quantify the residues of 11 β‐agonists in swine feeds with advantages of simple pretreatment and environmental friendliness.     

Surface Plasmon Resonance‐based Inhibitive Immunoassay Coupled with Dummy Template Molecularly Imprinted Polymer Solid Phase Extraction for On‐line Analysis of Trace Clenbuterol

A new indirect inhibitive immunoassay using surface plasmon resonance (SPR) coupled with molecularly imprinted polymer (MIP) was developed and applied for the analysis of trace clenbuterol (CL). A MIP coating using phenylephrine as the dummy template was synthesized in a flexible quartz capillary (30 cm×0.25 mm i.d.) by in situ polymerization technique, which then was used as the online solid phase extraction (SPE) tube before SPR detection. The thickness of the coating was 198 nm on average, illustrated by scanning electron microscope (SEM) image. The mechanism for adsorption of CL on dummy template MIP was found to be a Freundlich isotherm and pseudo‐second‐order model. The immunoassay was conducted on BIAcore 3000 biosensor automatically without pre‐treatment. The calibration curve was generated by linear fit in the range of 0.1–10 ng L^‐1 and 10–100 ng L^‐1. The detection limit was 0.1 ng L^–1, which is super sensitive. This method was directly applied for the analysis of real‐world samples without pretreatment.     

Selective extraction of fungicide carbendazim in fruits using β‐cyclodextrin based molecularly imprinted polymers

Considering the importance of developing a new analytical approach for pesticide residue detection for the sake of ensuring food safety, a β‐cyclodextrin based molecularly imprinted polymer was prepared for selective determination of carbendazim. The polymers consist of a porous and hollow structure demonstrating the selective abundant adsorption sites for carbendazim molecule. The selectivity and adsorption capacity of the imprinted polymers were analyzed with dispersive solid‐phase extraction and analyzed with high performance liquid chromatography coupled with ultraviolet. The results of imprinted polymers were higher than non‐imprinted polymers with the maximum adsorption capacity of 3.65 mg/g within 30 min of total adsorption time. The reusability of the imprinted polymers was determined to evaluate its effectiveness and stability, which proved that the polymers lost 10% efficiency within seven consecutive recycles. The developed method displayed good linearity over the concentration range of 0.05–2.0 mg/L. The recovery percentage of 81.33–97.23 with relative standard deviations of 1.49–4.66% was obtained from spiked apple, banana, orange, and peach samples with a limit of detection of 0.03 mg/L and a limit of quantification of 0.10 mg/L (signal to noise ratio = 3/10). The overall performance of the proposed method evident that this technique provided a desirable outcome and it can be used as a convenient approach, as it qualifies the analytical standards.     

Combined solid‐phase microextraction and high‐performance liquid chromatography with ultroviolet detection for simultaneous analysis of clenbuterol,salbutamol and ractopamine in pig samples

A simple and sensitive method based on the combination of solid‐phase microextraction (SPME) and high‐performance liquid chromatography with ultroviolet detection was developed for the simultaneous determination of clenbuterol, salbutamol and ractopamine in pig samples. Parameters of the SPME procedure affecting extraction efficiency, such as the type of fiber, extraction time, extraction temperature, ion strength, pH of sample and stirring rate, were optimized. The developed method was validated according to the International Conference on Harmonization guidelines. The calibration curves were linear over a range of 0.5–50 µg/L for clenbuterol and ractopamine, and 0.2–20 µg/L for salbutamol. The limits of detection were 0.1 µg/L for clenbuterol, 0.05 µg/L for salbutamol and 0.1μg/L for ractopamine, respectively. The averages of intra‐ and inter‐day accuracy ranged from 79.8 to 92.4%. The intra‐day and inter‐day precision were below 9.6% for the three analytes. This method exhibited the advantages of simplicity, rapidity and low solvent consumption, and was suitable for the monitoring of β₂‐agonists residue in pig samples. Copyright © 2013 John Wiley & Sons, Ltd.     

Novel method for the rapid and specific extraction of multiple β2‐agonist residues in food by tailor‐made Monolith‐MIPs extraction disks and detection by gas chromatography with mass spectrometry

A quick and specific pretreatment method based on a series of extraction clean‐up disks, consisting of molecularly imprinted polymer monoliths and C₁₈ adsorbent, was developed for the specific enrichment of salbutamol and clenbuterol residues in food. The molecularly imprinted monolithic polymer disk was synthesized using salbutamol as a template through a one‐step synthesis process. It can simultaneously and specifically recognize salbutamol and clenbuterol. The monolithic polymer disk and series of C₁₈ disks were assembled with a syringe to form a set of tailor‐made devices for the extraction of target molecules. In a single run, salbutamol and clenbuterol can be specifically extracted, cleaned, and eluted by methanol/acetic acid/H₂O. The target molecules, after a silylation derivatization reaction were detected by gas chromatography‐mass spectrometry. The parameters including solvent desorption, sample pH, and the cycles of reloading were investigated and discussed. Under the optimized extraction and clean‐up conditions, the limits of detection and quantitation were determined as 0.018–0.022 and 0.042–0.049 ng/g for salbutamol and clenbuterol, respectively. The assay described was convenient, rapid, and specific; thereby potentially efficient in the high‐throughput analysis of β₂‐agonists residues in real food samples.     

A Novel Electrochemical Sensor for β2‐Agonists with High Sensitivity and Selectivity Based on Surface Molecularly Imprinted Sol‐gel Doped with Antimony‐Doped Tin Oxide

A novel strategy to improve the sensitivity of molecularly imprinted polymer (MIP) sensors was proposed for the determination of β₂‐agonists. The imprinted sol‐gel film was prepared by mixing silica sol with a functional monomer of antimony‐doped tin oxide (ATO) and a template of β₂‐agonists. ATO, which was embedded in the surface of the molecularly imprinted sol‐gel film, not only provides the excellent conductivity for biosensor but also increases the stability and the surface area of the MIP film. The imprinted sensor was characterised by field emission scanning electron microscope, fourier transform infrared spectroscopy and electrochemical methods. Under the optimal experimental conditions, the peak current was linear with the logarithm of the concentration of clenbuterol (CLB) in the range of 5.5 nM–6.3 µM, and a detection limit of 1.7 nM was obtained. Meanwhile, the electrochemical sensor showed excellent specific recognition of the template molecule among structurally similar coexisting substances. Furthermore, the proposed sensor was satisfactorily applied to determine β₂‐agonists in human serum samples. The good results indicated that highly effective molecularly imprinted sol‐gel films doped with ATO can be employed for other analytes.     

Development of molecularly imprinted microspheres for the fast uptake of 4‐cumylphenol from water and soil samples

Molecularly imprinted microspheres containing binding sites for the extraction of 4‐cumylphenol have been prepared for the first time. The imprinted microspheres were synthesized by a precipitation method using 4‐cumylphenol as a template molecule, methacrylic acid as a functional monomer and divinylbenzene‐80 as a cross‐linker for polymer network formation. The formation and the morphology of molecularly imprinted microspheres were well characterized using infrared spectroscopy, thermogravimetric studies, and scanning electron microscopy. The Brunauer–Emmett–Teller analysis revealed the high surface area of the sorbent indicating formation of molecularly imprinted microspheres. The developed microspheres were employed as a sorbent for the solid‐phase extraction of 4‐cumylphenol and showed fast uptake kinetics. The sorption parameters were optimized to achieve efficient sorption of the template molecule, like pH, quantity of molecularly imprinted microspheres, time required for equilibrium set‐up, sorption kinetics, and adsorption isotherm. A standard method was developed to analyze the sorbed sample quantitatively at 279 nm using high‐performance liquid chromatography with diode array detection. It was validated by determining target analyte from synthetic samples, bottled water, spiked tap water, and soil samples. The prepared material is a selective and robust sorbent with good reusability.     

Determination of macrolide antibiotics residues in pork using molecularly imprinted dispersive solid‐phase extraction coupled with LC–MS/MS

A class‐specific macrolide molecularly imprinted polymer was synthesized by precipitation polymerization using tulathromycin as the template and methacrylic acid as the functional monomer. The polymers revealed different specific adsorption and imprinting factor for macrolides with different spatial arrangement of side chains as well as lactonic ring size. And the molecularly imprinted polymer possessed maximum adsorption capacity (54.1 mg/g) and highest imprinting factor (2.4) toward 15‐membered ring azithromycin. On the basis of molecularly imprinted polymer dispersive solid‐phase extraction, a rapid, selective, and reproducible method for simultaneous determination of seven macrolide antibiotics residues in pork was established by using liquid chromatography with tandem mass spectrometry. At spiking levels of 5, 10, 25, and 100 μg/kg, average recoveries of seven macrolides ranged from 68.6 to 95.5% with intraday and interday relative standard deviations below 8%. The limits of detection and limits of quantification were 0.2–0.5 and 0.5–2.0 μg/kg, respectively.     

Solid‐phase Extraction of β‐Sitosterol from Oldenlandia diffusa Using Molecular Imprinting Polymer

The β‐sitosterol imprinted polymer was prepared for selective extraction and analysis of β‐sitosterol from Oldenlandia diffusa (O. diffusa) followed by HPLC with UV detection. The imprinted polymers show high affinity and selectivity to β‐sitosterol. Using this molecularly imprinted polymer (MIP) cartridge as solid‐phase extraction (SPE) material, the interferences could be quickly washed out and β‐sitosterol was selectively retained and enriched. HPLC analysis method was used to evaluate the characteristics of this MIP material. At the condition of mobile phase composed of MeOH/H₂O/H₃PO₄ (99/1/0.1, V/V/V, pH=6.0) and the flow rate of 1.0 mL·min^?1, a good linear relationship was demonstrated when the concentrations of β‐sitosterol were in the range of 0.50–100.0 µg·mL^?1. The recoveries ranged from 75.3% to 86.5% and the inter‐day and intra‐day relative standard deviations were less than 5%. This developed HPLC method was proved to be acceptable for extraction of β‐sitosterol from O. diffusa.     

Selective extraction of bisphenol A from water by one‐monomer molecularly imprinted magnetic nanoparticles

One‐monomer molecularly imprinted magnetic nanoparticles were prepared as adsorbents for selective extraction of bisphenol A from water in this study. A single bi‐functional monomer was adopted for preparation of the molecularly imprinted polymer, avoiding the tedious trial‐and‐error optimizations as traditional strategy. Moreover, bisphenol F was used as the dummy template for bisphenol A to avoid the interference from residual template molecules. These nanoparticles showed not only large adsorption capacity and good selectivity to the bisphenol A but also outstanding magnetic response performance. Furthermore, they were successfully used as magnetic solid‐phase extraction adsorbents of bisphenol A from various water samples, including tap water, river water, and seawater. The developed method was found to be much more efficient, convenient, and economical for selective extraction of bisphenol A compared with the traditional solid‐phase extraction. Separation of these nanoparticles can be easily achieved with an external magnetic field, and the optimized adsorption time was only 15 min. The recoveries of bisphenol A in different water samples ranged from 85.38 to 93.75%, with relative standard deviation lower than 7.47%. These results showed that one‐monomer molecularly imprinted magnetic nanoparticles had the potential to be popular adsorbents for selective extraction of pollutants from water.     

Preparation and Characterization of Prometryn Molecularly Imprinted Solid‐Phase Microextraction Fibers

Abstract

A novel reproducible solid‐phase microextraction (SPME) coating was prepared on the surface of silanized silica fibers by molecularly imprinted polymerization using prometryn as template molecule. The structure and extraction performance of molecularly imprinted polymer (MIP) coating was studied with the scanning electron microscope and high performance liquid chromatography (HPLC). Specific selectivity was found with the prometryn MIP‐coated fiber to prometry and its structural analogues such as atrazine, simetryn, terbutylazin, ametryn, propazine and terbutryn. In contrast, these triazines could not be selectively extracted by the non‐imprinted polymer fiber or commercial polydimethylsiloxane (PDMS), polydimethylsiloxane/divinylbenzene (PDMS/DVB), polyacrylate (PA) fibers.     

Molecularly imprinted solid-phase extraction for the selective HPLC determination of ractopamine in pig urine

A method was developed for the determination of ractopamine in pig urine using molecularly imprinted solid-phase extraction (MISPE) as the sample clean-up technique combined with high-performance liquid chromatography. The molecularly imprinted polymer (MIP) was synthesized in acetonitrile-triethylamine system using ractopamine (RAC) as the template and acrylamide as the monomer. The binding capacity of the polymer toward RAC was found to be about 2.57 mg of ractopamine/g of polymer. The optimal procedures for MISPE consisted of conditioning with 3 mL methanol, equilibrating with 3 mL of water, loading volume of <10 mL of aqueous sample (pH 7), washing with 3 mL water and 3 mL methanol, and eluting with 5 mL of 5% ammonia in methanol. In the four spiked samples with the levels of 0.01, 0.1, 1.0 and 5.0 μg/mL, the mean recoveries of analyte on the MIP were higher than 90% with relative standard deviation <10%, and significant differences between imprinted and non-imprinted materials were observed. The MIP selectivity was evaluated by checking 11 drugs with similar and different molecular structures to that of RAC. The characteristics of three-dimensional cavities and hydrogen bond interaction were regarded as the main factors that dominated the retention of RAC on the MISPE cartridge.     

Solid‐phase extraction based on a molecularly imprinted polymer for the selective determination of four benzophenones in tap and river water

This work reports the preparation of molecularly imprinted polymer particles for the selective extraction and determination of four benzophenones from aqueous media. The polymer was prepared by using 4‐vinylpridine as functional monomer, ethylene glycol dimethacrylate as cross‐linker, acetonitrile as porogenic solvent and 2,2’,4,4’‐tetrehydroxybenzophenone as template. Good specific adsorption capacity (Q_max = 27.90 μmol/g) for 2,2’,4,4’‐tetrehydroxybenzophenone was obtained in the sorption experiment and good class selectivity for 2,2’,4,4’‐tetrehydroxybenzophenone, 2,4‐dihydroxybenzophenone, 2,2’‐dihydroxy‐4‐methoxybenzophenone, 2,2’‐dehydroxy‐4,4’‐dimethoxybenzophenone was demonstrated by the chromatographic evaluation experiment. Factors affecting the extraction efficiency of the molecularly imprinted solid‐phase extraction procedure were investigated systematically. An accurate and sensitive analytical method based on the molecularly imprinted solid‐phase extraction coupled with high‐performance liquid chromatography and diode array detection has been successfully developed for the simultaneous determination of four benzophenones from tap water and river water with method detection limits of 0.25–0.72 ng/mL. The recoveries of benzophenones for water samples at two spiking levels (500 and 5000 ng/mL for each benzophenone) were in the range of 86.9–103.3% with relative standard deviations (n = 3) below 9.2%.     

Selective solid‐phase extraction of artificial chemicals from milk samples using multiple‐template surface molecularly imprinted polymers

A novel multiple‐template surface molecularly imprinted polymer (MTMIP) was synthesized using ofloxacin and 17β‐estradiol as templates and modified monodispersed poly(glycidylmethacrylate‐co‐ethylene dimethacrylate) (P_GMA/EDMA) beads as the support material. Static adsorption, solid‐phase extraction and high‐performance liquid chromatography were performed to investigate the adsorption properties and selective recognition characteristics of the polymer templates and their structural analogs. The maximum binding capacities of ofloxacin and 17β‐estradiol on the MTMIP were 9.0 and 6.6 mg/g, respectively. Compared with the corresponding nonimprinted polymer, the MTMIP exhibited a much higher adsorption performance and selectivity toward three quinolones and three estrogens, which are common drug residues in food. The MTMIP served as a simple and effective pretreatment method and could be successfully applied to the simultaneous analysis of multiple target components in complex samples. Furthermore, the MTMIP may find useful applications as a solid‐phase absorbent in the simultaneous determination of trace quinolones and estrogens in milk samples, as the recoveries were in the range 77.6–98.0%. Copyright © 2015 John Wiley & Sons, Ltd.     

Preparation and selective recognition of a novel solid‐phase microextraction fiber combined with molecularly imprinted polymers for the extraction of parabens in soy sample

A prepared molecularly imprinted polymer with ethyl p‐hydroxybenzoate as template molecule was applied for the first time to a homemade solid‐phase microextraction fiber. The molecularly imprinted polymer‐coated solid‐phase microextraction fiber was characterized by scanning electron microscopy and thermogravimetric analysis. Various parameters were investigated, including extraction temperature, extraction time, and desorption time. Under the optimum extraction conditions, the molecularly imprinted polymer‐coated solid‐phase microextraction fiber exhibited higher selectivity with greater extraction capacity toward parabens compared with the nonimprinted polymer‐coated solid‐phase microextraction fiber and commercial fibers. The molecularly imprinted polymer‐coated solid‐phase microextraction fiber was tested using gas chromatography to determine parabens, including methyl p‐hydroxybenzoate, ethyl p‐hydroxybenzoate, and propyl p‐hydroxybenzoate. The linear ranges were 0.01–10 μg/mL with a correlation coefficient above 0.9943. The detection limits (under signal‐to‐noise ratio of 3) were below 0.30 μg/L. The fiber was successfully applied to the simultaneous analysis of three parabens in spiked soy samples with satisfactory recoveries of 95.48, 97.86, and 92.17%, respectively. The relative standard deviations (n=6) were within 2.83–3.91%. The proposed molecularly imprinted polymer‐coated solid‐phase microextraction method is suitable for selective extraction and determination of trace parabens in food samples.