Trimethylolpropane Trimethacrylate Research Articles

Functionalization of an alkyd resin with (meth)acrylate groups for photoinitiated polymerization

Alkyd resin based on phthalic acid, soybean oil, pentaerythritol, and a small amount on fumaric acid was synthesized and functionalized with (meth)acrylate groups. Functionalization was carried out in two different ways. These were direct acrylation of the alkyd resin using acrylic acid and N-bromo succinimide on the one hand and a two step synthesis starting with epoxidation of the internal double bonds comprising in the alkyd resin followed by ring opening reaction with (meth)acrylic acid in a consecutive reaction on the other hand. The (meth)acrylate functionalized alkyd resins were characterized by 1H- and 13C NMR spectroscopy, FT-IR spectroscopy, GPC, iodine value (IN), and glass transition temperature (Tg). Photoinitiated polymerization of the functionalized alkyd resins using bis(4-methoxybenzoyl) diethyl germanium as photoinitiator was investigated by photo-DSC under nitrogen and in the presence of air. The maximum of the polymerization rate (Rpmax), the time (tmax) to obtain Rpmax, and the conversion on double bonds give information about the strong increase in the reactivity of the (meth)acrylate functionalized alkyd resins caused by their (meth)acrylate substituents. Additional bromo or hydroxy substituent attribute to reactivity differences between the functionalized alkyd resins. Moreover, (meth)acrylate functionalized alkyd resins were investigated as additives (10 wt %) in traditional monomers (1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate) or in acrylate functionalized methyl oleate model monomers. Photo-DSC investigation of the mixtures under nitrogen and in the presence of air showed no significant influence of the hydroxy substituted (meth)acrylated alkyd resin additives on photopolymerization kinetics of the traditional monomers. Although incorporation of bromine into the acrylated alkyd resin resulted in a slight decrease of both the Rpmax value and the conversion on double bonds if used as additive in a mixture comprising trimethylolpropane triacrylate or 9-acryloyloxy-10-bromo methyl oleate. Hydroxy substituted (meth)acrylated alkyd resins may be prefered as additives in traditional monomers.

Bamboo fibers composites based on styrene-free soybean-oil thermosets using methacrylates as reactive diluents

The present work aims at preparation of green composites by using bamboo fibers (BFs) as reinforcements and styrene-free soybean-oil based thermosets as matrices. To facilitate the formulation of acrylated epoxidized soybean oil (AESO) resins with a low viscosity and high crosslinking density, two methacrylate monomers, i.e., 1,4-butanediol dimethacrylate (BDDMA) and trimethylolpropane trimethacrylate (TMPTMA) were respectively used as reactive diluents (RDs) for replacing anticipatory carcinogenic styrene. Results indicated that the crosslinking density of AESO resins was improved and their viscosities were reduced simultaneously. The rheological and curing behaviors of AESO resins incorporated with RDs were investigated. The static and dynamic mechanical performance and thermal properties of bamboo fibers composites with the novel AESO resins were tested.

Surface molecularly imprinted polymers prepared by two-step precipitation polymerization for the selective extraction of oleanolic acid from grape pomace extract.

Surface molecularly imprinted polymers were successfully prepared by a novel two-step precipitation polymerization method. The first-step allowed the formation of 4-vinylpyridine divinylbenzene and trimethylolpropane trimethacrylate copolymeric microspheres. In the second-step precipitation polymerization, microspheres were modified with a molecularly imprinting layer of oleanolic acid as template, methacrylic acid as functional monomer, and divinylbenzene/ethylene glycol dimethacrylate as cross-linker. The obtained polymers had an average diameter of 4.43μm and a polydispersity index of 1.011; adsorption equilibrium was achieved within 40min, with adsorption capacity reaching 27.4mg/g. Subsequently, the polymers were successfully applied as the adsorbents of molecularly imprinted solid-phase extraction to separateand purifythe oleanolic acid from grape pomace. The content of oleanolic acid in the grape pomace extract was enhanced from 13.4 to 93.2% after using the molecularly imprinted solid-phase extraction process. This work provides an efficient way for effective oleanolic acid separation and enrichment from complex matrices, which is especially valuable in industrial production.

Magnetic molecularly imprinted polymer prepared by microwave heating for confirmatory determination of chloramphenicol in chicken feed using high-performance liquid chromatography-tandem mass spectrometry

A magnetic molecularly imprinted polymer (MMIP) for chloramphenicol was prepared using a surface-imprinted and microwave-heating-induced polymerization method. The surfaces of the magnetic particles were first double-bond functionalized with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS), followed by the copolymerization of 4-vinyl pyridine (4-VP) and trimethylolpropane trimethacrylate (TRIM) in the presence of chloramphenicol as a template and 1,1-azobis(cyclohexane-carbonitrile) (ABCN) as an initiator in a mixture of dimethyl sulfoxide and water with microwave heating at 80°C. The magnetic polymer possesses supraparamagnetic properties and was used to concentrate and cleanup chicken feed extract, followed by chromatographic separation using a Lichrospher®100 RP C8 column and detection with two multi-reaction monitoring transitions at m/z 321→ 152 and m/z 321→ 257. The mean recoveries obtained at two spiking levels were in the range of 94.6–100% The relative intra- and inter-day standard deviations were in the range of 1.4–2.6% and 5.1–5.7%, respectively. The detection limit of the method was 0.12 µg kg−1. This confirmatory method was successfully applied to determine chloramphenicol in chicken feed samples.

Improving the ceramic yield of polycarbosilane by radiation cross‐linking in the presence of multifunctional monomers

AbstractAn interesting method for radiation cross‐linking polycarbosilane (PCS) at high efficiency and low cost was developed by adding multifunctional monomers (trimethylolpropane trimethacrylate (TMPTMA) or divinylbenzene (DVB)). The effect of multifunctional monomers on the radiation cross‐linking and ceramic yield of PCS was investigated. The results revealed that the addition of a small amount of multifunctional monomer can substantially improve the ceramic yield and reduce the absorbed dose by promoting cross‐linking. The ceramic yields of radiation cross‐linked “PCS/2%DVB (300 kGy)” and “PCS/2%TMPTMA (300 kGy)” were 74 wt% and 78 wt%, respectively, while that of the radiation cross‐linked “PCS (300 kGy)” was only 64 wt%. The presence of double bonds in multifunctional monomers stimulated the combination reactions of free radicals in PCS induced by γ‐ray irradiation and subsequently enhanced the efficiency of cross‐linking. Furthermore, it was found that the incorporation of a small amount of multifunctional monomer hardly affected the chemical composition and crystallization behavior of the final SiC ceramics.

Development of an in-house mixed-mode solid-phase extraction for the determination of 16 basic drugs in urine by High Performance Liquid Chromatography-Ion Trap Mass Spectrometry

The aim of the present work was to develop a novel in-house mixed-mode SPE sorbent to be used for the HPLC-Ion TrapMS determination of 16 basic drugs in urine.By using a computational modelling, a virtual monomer library was screened identifying three suitable functional monomers, methacrylic acid (MAA), itaconic acid (IA) and 2-acrylamide-2-methylpropane sulfonic acid (AMPSA), respectively. Three different sorbents were then synthetized based on these monomers, and using as cross-linker trimethylolpropane trimethacrylate (TMPTMA).The sorbent characterization analyses brought to the selection of the AMPSA based phase.Using this novel in-house sorbent, a SPE-HPLC-Ion TrapMS method for drug analysis in urine was validated proving to be selective and accurate and showing a sensitivity adequate for toxicological urine analysis. The comparison of the in-house mixed-mode SPE sorbent with two analogous commercial mixed-mode SPE phases showed that the first one was better not only in terms of process efficiency, but also in terms of quality-price rate.To the best of our knowledge, this is the first time in which an in-house SPE procedure has been applied to the toxicological analysis of a complex matrix, such as urine.

Magnetic Field-Induced Polymerization of Molecularly Imprinted Polymers

In this work, we developed a novel approach for the preparation of molecularly imprinted polymer (MIP) coatings directly onto magnetic multicore nanoparticles (MMCs) using alternating magnetic fields to trigger the polymerization reaction. MIPs were synthesized with rhodamine 123 (R123) as model template molecule, methacrylic acid as functional monomer, and trimethylolpropane trimethacrylate as cross-linker. The amount of iron oxide nanoparticles and the composition of the polymerization mixture were optimized to enable the thermal polymerization of a thin MIP shell on each MMC using electromagnetic heating without altering the properties of the recognition layer. The thickness of the polymerized MIP layer grafted onto the MMCs was fine-tuned by adjusting the dose of electromagnetic field (101.4 kHz, total power dissipation = 105 W). The resulting magnetic multicore MIP nanoparticles (MMC-MIPs) were characterized by Fourier transform infrared and X-ray diffraction spectroscopy, transmission electron micro...

Effects of hydrophilic monomers on sorptive properties of divinylbenzene-based reversed phase sorbents

Solid phase extraction (SPE) has been extensively used as a pretreatment method. In SPE methods, commercially available reversed phase type sorbents, which consist of macroporus styrene-divinylbenzene or copolymers including divinylbenzene (DVB) and hydrophilic monomers, have been applied to a variety of samples. The later sorbents are called hydrophilic lipophilic balanced (HLB) type sorbents. Hydrophilic monomers in hydrophilic lipophilic balanced type sorbents contribute to the increase in retention of polar compounds, because hydrophilic monomers improve the wettability and increase the interaction with polar compounds as analytes. In this study, three different methacrylate monomers (ethylene glycol dimethacrylate (EGDMA), glycerol dimethacrylate (GDMA) and trimethylolpropane trimethacrylate (TMPTMA)), which are expected to improve the retention of polar compounds, were chosen, and DVB-based copolymetric sorbents including the three monomers were newly synthesized. Among them, the sorbents including GDMA or TMPTMA gave higher recoveries to polar compounds such as uridine and adenine than that including EGDMA. The optimization studies of hydrophilic lipophilic balance, inert diluent and the purity of DVB improved the sorptive abilities of the sorbents. The developed sorbents have higher recoveries for variety of polar compounds (cytosine, uracil, cytidine, uridine, 2′-deoxycytidine, 2′-deoxyguanosine, adenine, thymidine, adenosine and 2′-deoxyadenosine) than commercially available hydrophilic lipophilic balanced type sorbents, while the recoveries for theophylline were comparable between the proposed sorbents and the commercial sorbents.

Novel ferrocene-containing organosilicon polymers and uniform microspheres prepared by free radical copolymerization: Precursors for magnetic Si-C-Fe-(O) nanomaterials

Ferrocene-containing organosilicon polymers demonstrate wide applications in catalysts, redox sensors, ceramic nanomaterials and nanolithography fields. However, most synthesis methods for ferrocene-containing organosilicon polymers require either strict water-free and oxygen-free conditions or the presence of platinum complex catalysts. In this contribution, the free radical copolymerization of 1, 1′‑bis(dimethylvinylsilyl)ferrocene (DVFc) and trimethylolpropane trimethacrylate (TMPTMA) was achieved to construct either soluble branched ferrocene-containing organosilicon polymers or uniform cross-linked microspheres only through the feed ratio tuning of the two monomers. The structures of copolymer and cross-linked microspheres have been characterized by one-dimensional nuclear magnetic resonance (1D NMR) and two-dimensional (2D) NMR measurements. Furthermore, the novel organosilicon polymers could be employed as preceramic precursors to prepare magnetic Si-C-Fe-(O) ceramics with favorable ceramic yield at high temperature. The nanocrystals-containing ceramics magnetism could be tuned through copolymer nature or pyrolysis condition variations.

Poly(trimethylolpropane trimethacrylate) modified with esters derivatives of 3-phenylprop-2-en-1-ol

The main objective of this paper was to study the influence of the diesters derivatives of naturally occurring alcohol: 3-phenylprop-2-en-1-ol, on the thermal, viscoelastic and mechanical properties of bulk poly(trimethylolpropane trimethacrylate) [poly(TRIM)]. The bulk poly(TRIM) networks were obtained by mixing trimethylolpropane trimethacrylate with 0.5, 1, 2, 3, 5, 10 and 20 mass% of diesters and polymerized in the presence of 1.5 mass% of benzoyl peroxide in the temperature range from 50 to 80 °C. Generally, bulk poly(TRIM) modified with esters derivatives of 3-phenylprop-2-en-1-ol was characterized by lower stiffness, lower glass transition temperature, lower thermal stability, lower hardness and heat deflection temperature values, and higher tensile strength and percentage elongation, especially for compositions containing higher diester content as compared to pure, bulk poly(TRIM).

Determination of sulfonylurea herbicide residues in tobacco leaves by molecularly imprinted-solid phase extraction-high performance liquid chromatography

Molecularly imprinted polymer (MIP) micro-particles were prepared in dichloromethane (DCM) by precipitation polymerization using chlorsulfuron (CS) as a template molecule, α -methacrylic acid (MAA) as a functional monomer, and trimethylolpropane trimethacrylate (TRIM) as a cross-linker. The pretreatment process of the tobacco sample spiked with chlorsulfuron, metsulfuron-methyl, bensulfuron-methyl, tribenuron-methyl, ethametsulfuron, and nicosulfuron, was performed using a chlorsulfuron molecularly imprinted polymer solid phase extraction (CS-MIP-SPE) column prepared with CS-MIP as the sorbent. High performance liquid chromatography (HPLC) was subsequently used for quantitative analysis. In this way, a detection technique for sulfonylurea herbicide residues in tobacco leaves was developed using CS-MIP-SPE as a pretreatment method and HPLC as an analytical tool. The results showed that the methods can be applied to the determination of the six sulfonylurea herbicides in tobacco samples. At spiking contents ranging from 0.50 to 50 μg/g, the recoveries for the six sulfonylurea herbicides in tobacco samples were 77.60%-102.05%, with relative standard deviations of 0.16% to 7.07%, and detection limits of 0.08-0.46 μg/g. With its unique advantages, the MIP-SPE-HPLC method provides a multi-residue analytical platform that can meet the requirements of simultaneous determination of sulfonylurea herbicides in tobacco samples.

Rapid Analysis of Bitertanol in Agro-products Using Molecularly Imprinted Polymers-Surface-Enhanced Raman Spectroscopy

In this work, we first reported molecularly imprinted polymers-surface-enhanced Raman spectroscopy (MIP-SERS) for rapid detection and quantification of bitertanol in cucumber and peaches. In order to remove interference-mitigation effects and avoid template leakage, MIPs were successfully synthesized based on triadimefon molecules as the dummy template, methacrylic acid (MAA) as a functional monomer, trimethylolpropane trimethacrylate (TRIM) as a cross-linker, and 2,2-azobis-isobutyronitrile (AIBN) as an initiator. Static adsorption experiments and Scatchard analysis were then conducted and results showed that the synthesized MIPs could rapidly and selectively adsorb and separate bitertanol from cucumber and peaches due to their predetermined recognition sites. The capacity of MIPs for absorbing bitertanol (∼ 2.21 mg/g) was approximately 1.5 times that of non-imprinted polymers (NIPs) (∼ 1.55 mg/g). Gold nanoparticles (AuNPs) synthesized by sodium citrate reduction method were validated as a suitable SERS colloid for enhancing Raman signals. SERS spectral peaks (760, 985, 1190, and 1279 cm−1) were used to develop quantitative analysis based on partial least-squares regression (PLSR) for bitertanol in cucumber and peaches. The LODs for this method were 0.041 and 0.029 mg/kg in cucumber and peaches, respectively. The entire analysis process required 15 min or less. More importantly, the MIP-SERS system provided not only a rapid, sensitive, and reliable method for bitertanol detection, but also a routine for overcoming the interference-mitigation effects in the SERS technology.

Facile fabrication of gradient density organic aerogel foams via density gradient centrifugation and UV curing in one-step

Gradient density porous materials have played an important role in areas of aerospace, biomaterials and high-energy absorption experiments. In order to accurately control the process of gradient forming, a new approach was proposed to produce gradient density porous materials. By using dibutyl phthalate as the solvent and benzoin methyl ether as the photoinitiator, gradient density trimethylolpropane trimethacrylate (TMPTMA) foams were fabricated after the density gradient centrifugation, ultraviolet curing and CO2 supercritical drying. The microstructure and density distribution of foams were characterized by nitrogen adsorption, mercury injection apparatus test, scanning electron microscopy, UV–visible absorption spectrum, X-ray phase contrast, and dynamic mechanical analysis. Moreover, the storage modulus of organic foams was significantly improved by the gradient change of foam density. The results indicated that this approach was an effective method for the preparation of gradient density organic foams and could be suitable for producing gradient density porous materials derived from a sol–gel process. We presented a new approach for the preparation of gradient density TMPTMA aerogel foams via density gradient centrifugation and UV curing in one-step. It was the first report so far to rationally design and facilely fabricate TMPTMA foams. The results definitively proved the density distribution of a linear gradient for foams. The approach could be simple and suitable for producing other gradient density porous materials derived from a sol–gel process. Different gradient parameters of TMPTMA foams could be obtained by monitoring the target density of mixture solutions, the sloping angle, and the size of the tube, respectively. Furthermore, it could be seen that the method of analyzing absorbance was actually a suitable tool to observe the density distribution of TMPTMA foams, which showed an intuitionistic figure to realize the density distribution. As a result, it could be believed that this approach could be useful for fabrication of gradient density porous materials in future.

Polymer monoliths with silver nanoparticles-cholesterol conjugate as stationary phases for capillary liquid chromatography

Monoliths in fused-silica capillaries were prepared by an in-situ polymerization using glycidyl methacrylate (GMA) as a functional monomer and in the presence of different crosslinkers such as ethylene dimethacrylate (EDMA), trimethylolpropane trimethacrylate (TRIM), 1,6-hexanediol dimethacrylate (HEDMA), pentaerythritol tetraacrylate (PETeA), triethylene glycol dimethacrylate (TriEDMA), while azobisisobutyronitrile (AIBN) was an initiator. The monoliths’ surfaces were modified chemically with cystamine dihydrochloride, followed by immobilization of Ag-NPs the surface of which was functionalized with cholesterol cysteamine (Chol-SH). Such a new material enabled the separation of proteins in a reversed phase mode. The influence of the kind of a cross-linker and composition of the porogenic solutions on the porosity and separation properties of the obtained polymers was investigated and discussed. It was found that the amount of Ag-NPs embedded on the monoliths’ surfaces depended on the porous properties of the monoliths, which was directly connected with the kind of the cross-linkers used. For the determination of the amount of the attached Ag-NPs the thermogravimetric analysis was used and additionally the ISEC method as a comparative method was also proposed. It was found that the maximum amount (about 20% by weight) of the 10nm Ag-NPs was attached to the poly(GMA-EDMA) and poly(GMA-TRIM) monoliths.

Cytotoxicity and DNA double-strand breaks in human gingival fibroblasts exposed to eluates of dental composites

ObjectivePreviously, single composite components were used to study cytotoxicity and induction of DNA double-strand breaks (DNA-DSBs) of dental composite resins. In the present study, cytotoxicity and induction of DNA-DSBs in human gingival fibroblasts (HGFs) were investigated with dental composite eluates consisting of multiple components. The eluates were qualified and quantified. MethodsThe composites Esthet.X® HD, Venus®, X-tra fil®, CLEARFIL™ AP-X, Admira® Fusion and QuiXfil® were polymerized and immersed into Dulbecco’s modified Eagle’s medium (DMEM) for 72h. Subsequently, HGFs were incubated with the corresponding composite eluates. The cell viability of HGFs was obtained from an XTT assay. DNA-DSBs were determined using a γ-H2AX assay. The qualification and quantification of eluates were performed by gas chromatography/mass spectrometry (GC/MS). ResultsHGFs exposed to the eluates of all investigated composites showed no significant loss of cell viability, compared to negative control. Significant DNA-DSBs induction could be found in HGFs exposed to the eluates of Esthet.X® HD (0.43±0.05 foci/cell) and Venus® (0.39±0.04 foci/cell), compared to control (0.22±0.03 foci/cell). A total of 12 substances were detected from the investigated composite eluates. Five of them were methacrylates: tetraethyleneglycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), ethyleneglycol dimethacrylate (EGDMA) and trimethylolpropane trimethacrylate (TMPTMA). The highest concentration of HEMA (110.5μM), HPMA (86.08μM) and TMPTMA (4.50μM) was detected in the eluates of QuiXfil®. The highest concentration of TEGDMA was 1080μM in Venus® eluates and the highest concentration of EGDMA was 3.18μM in Esthet.X® HD eluates. SignificanceSignificant DNA-DSBs induction can be found in HGFs exposed to the eluates of Esthet.X® HD and Venus®. The interactive effects among released (co)monomers and additives may influence the cytotoxicity and induction of DNA-DSBs, compared to exposure with single composite component.

Effects of NCO/OH Ratio and Reactive Diluent Type on the Adhesion Strength of Polyurethane Methacrylates for Cord/Rubber Composites

ABSTRACTA series of dual curable polyurethane methacrylate-based oligomers were synthesized by changing the NCO:OH ratio and then were included in adhesive formulations using trimethylolpropane trimethacrylate and tricyclodecane dimethanol diacrylate (TCDDA) as reactive diluents. The effects of NCO:OH ratio and reactive diluent type on the structural properties of UV-cured free films and adhesion properties between polyester cord/rubber surfaces were studied. The highest adhesion strength of the 103 N cm−1 was obtained when the NCO:OH ratio was set as 4 and the TCDDA was used as a reactive diluent.

Controlled crosslinking of trimethylolpropane trimethacrylate for preparation of organic monolithic columns for capillary liquid chromatography.

Organic monolithic columns based on single crosslinking of trimethylolpropane trimethacrylate (TRIM) monomer were prepared in a single step by living/controlled free-radical polymerization. Full optimization of the preparation, such as using different percentages of TRIM and different amounts of radical promoter as well as various porogen solvents were explored. The resulting monolithic columns were characterized by scanning electronic microscopy and nitrogen sorption for structure morphology studies and surface area measurements, respectively. Using capillary liquid chromatography, 150μm i.d. columns were applied to separate a mixture of small hydrophobic molecules. The results indicated that column performance is highly sensitive to the type and the amount of porogen solvents used in the polymerization mixture composition. Good resolution factors and methylene selectivity were obtained, indicating the promising potential of this material for capillary liquid chromatography separations.

Solid-phase extraction of the alcohol abuse biomarker phosphatidylethanol using newly synthesized polymeric sorbent materials containing quaternary heterocyclic groups

Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5μM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC–MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6%±6.4%.

Selective solid-phase extraction based on molecularly imprinted technology for the simultaneous determination of 20 triazole pesticides in cucumber samples using high-performance liquid chromatography-tandem mass spectrometry.

A selective analytical method for the simultaneous determination of 20 triazole fungicides and plant growth regulators in cucumber samples was developed using solid-phase extraction with specific molecularly imprinted polymers (MIPs) as adsorbents. The MIPs were successfully prepared by precipitation polymerization using triadimefon as the template molecule, methacrylic acid as the functional monomer, trimethylolpropane trimethacrylate as the crosslinker, and acetonitrile as the porogen. The performance and recognition mechanism for both the MIPs and non-molecularly imprinted polymers were evaluated using adsorption isotherms and adsorption kinetics. Liquid chromatography-tandem quadrupole mass spectrometry was used to identify and quantify the target analytes. The solid-phase extraction using the MIPs was rapid, convenient, and efficient for extraction and enrichment of the 20 triazole pesticides from cucumber samples. The recoveries obtained at three concentration levels (1, 2, and 10μgL-1) ranged from 82.3% to 117.6% with relative standard deviations of less than 11.8% (n=5) for all analytes. The limits of detection for the 20 triazole pesticides were all less than 0.4μgL-1, and were sufficient to meet international standards.

Molecularly imprinted polymers immobilized on 3D printed scaffolds as novel solid phase extraction sorbent for metergoline

In the present work, a novel solid phase extraction (SPE) sorbent was developed based on molecularly imprinted polymers (MIPs) immobilized on 3D-printed scaffolds using polymer networks as MIP-immobilizing layer. MIPs were produced by precipitation polymerization in acetonitrile (ACN) using methacrylic acid (MAA) as functional monomer, trimethylolpropane trimethacrylate (TRIM) as crosslinker and metergoline as model template which allows final recognition of ergot alkaloid mycotoxins. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) analyses showed an average MIP particle size of 457 ± 145 nm. Functional MIP analysis revealed dissociation constants (KD) of 0.29 and 38.90 μM for high and low affinity binding sites respectively. Subsequently, crosslinking of polymer network building blocks was applied as MIP immobilization method on poly-ε-caprolactone (PCL) which was selected as polymer model. Methodology optimization and subsequent evaluation were first realized on 2D PCL surfaces. Based on analyses such as optical evaluation of MIP availability after immobilization through SEM and depth profilometry, an optimal polymer network building block concentration of 7.5 w/w% was selected. In a final part, transfer of MIP immobilization to 3D PCL scaffolds was successfully realized. Functional analysis showed that the newly developed SPE sorbents were able to rebind 44.87 ± 8.30% of a 1 μM metergoline solution. In conclusion, a new type of SPE sorbent was developed for the detection of metergoline by the use of MIP-functionalized polymer scaffolds. The applied technology opens up future possibilities for the extraction of a broad range of components such as other mycotoxins.