Polymeric Sorbent Research Articles

Tailored Polymer-Based Selective Extraction of Lipid Mediators from Biological Samples.

Lipid mediators, small molecules involved in regulating inflammation and its resolution, are a class of lipids of wide interest as their levels in blood and tissues may be used to monitor health and disease states or the effect of new treatments. These molecules are present at low levels in biological samples, and an enrichment step is often needed for their detection. We describe a rapid and selective method that uses new low-cost molecularly imprinted (MIP) and non-imprinted (NIP) polymeric sorbents for the extraction of lipid mediators from plasma and tissue samples. The extraction process was carried out in solid-phase extraction (SPE) cartridges, manually packed with the sorbents. After extraction, lipid mediators were quantified by liquid chromatography–tandem mass spectrometry (LC–MSMS). Various parameters affecting the extraction efficiency were evaluated to achieve optimal recovery and to reduce non-specific interactions. Preliminary tests showed that MIPs, designed using the prostaglandin biosynthetic precursor arachidonic acid, could effectively enrich prostaglandins and structurally related molecules. However, for other lipid mediators, MIP and NIP displayed comparable recoveries. Under optimized conditions, the recoveries of synthetic standards ranged from 62% to 100%. This new extraction method was applied to the determination of the lipid mediators concentration in human plasma and mouse tissues and compared to other methods based on commercially available cartridges. In general, the methods showed comparable performances. In terms of structural specificity, our newly synthesized materials accomplished better retention of prostaglandins (PGs), hydroxydocosahexaenoic acid (HDoHE), HEPE, hydroxyeicosatetraenoic acids (HETE), hydroxyeicosatrienoic acid (HETrE), and polyunsaturated fatty acid (PUFA) compounds, while the commercially available Strata-X showed a higher recovery for dihydroxyeicosatetraenoic acid (diHETrEs). In summary, our results suggest that this new material can be successfully implemented for the extraction of lipid mediators from biological samples.

Polymer Sorbents from “Nitron Fiber Waste”

New sorbents were synthesized from nitron fiber waste modified with various anion-exchange groups. The structure was studied by potentiometric titration and IR spectroscopy. The possibility ихof using them for immobilizationis shown, andthe physicochemical characteristics of polymer sorbentsare studied.

Creating of highly hydrophobic sorbent with fluoroalkyl silane cross-linker for efficient oil-water separation

Hydrophobic sorbents with good hydrophobicity and high porosity have drawn attention for removing oil spills from water. In this study, a highly reusable hybrid polymeric sorbent was successfully fabricated by the reaction of Polydimethylsiloxane (PDMS) and fluorinated alkyl silanes via bulk polymerization without using any activator, initiator, or catalyst. The fabricated polymer sorbent exhibits good hydrophobicity and porous structure; thus, it can be applied as a sorbent for the removal of oils from wastewater. The hybrid sorbents presented high hydrophobicity and excellent sorption capacity for a variety of oils and organic liquids, and the sorption capacity ranges between ~500–1800%. Due to its hydrophobic structure, it can selectively absorb oil from the bottom and the water surface, immediately. Its easy one-pot fabrication procedure, high oil sorption capacity, quick sorption-desorption cycles and great reusability without any capacity loss make it a very promising material for oil spill applications.

Comparison study of nanofibers, composite nano/microfiber materials, molecularly imprinted polymers, and core-shell sorbents used for on-line extraction-liquid chromatography of ochratoxins in Tokaj wines

On-line solid phase extraction coupled with liquid chromatography enables high sample throughput, preconcentration of analytes, efficient clean-up, and separation in a single step. Our comparison study focused on the selection of an optimal SPE sorbent for on-line extraction of ochratoxins A and B allowing fast and sensitive control of mycotoxin contamination. Four types of fibrous sorbents including polyethylene microfibers, polypropylene microfibers, polycaprolactone microfibers/nanofibers composite, and polycaprolactone microfibers/polyvinylidene difluoride nanofibers composite together with selective molecularly imprinted polymers, and conventional C18 core–shell particle sorbent were tested, and efficiency of extraction was compared in on-line mode. Clean-up efficiency and ability to remove matrix interferences with the subsequent chromatographic separation were optimized for all extraction materials followed by validation of the methods. Both nanofibers and molecularly imprinted polymer sorbents were packed in a stainless-steel cartridge and directly connected to the HPLC system. Only polyethylene microfibers among all the tested fibers achieved the selectivity desired for resolution of ochratoxins from the wine matrix with the validation parameters comparable to commercial C18 sorbent. The best results featuring a limit of detection 0.03–0.06 µg L-1, recoveries 92–97% with RSD < 2%, and only 6 min overall analysis time were obtained after extraction using C18 particles. Features including stability of fibers in organic solvents, under high pressure, and their multiple reusability were also proven. Comparison of several types of extraction sorbents for ochratoxins was demonstrated with their on-line extraction followed by liquid chromatography with fluorescence determination using Tokaj wine as a complex matrix.

Preparation and characterized study of new molecularly imprinted polymers for determination Cocaine by GC-Mass based on different Functional Monomers

Molecularly imprinted polymers (MIP) Showing high selectivity and affinity with an increasingly increasing analysis is now seen in the predetermined molecule (template) Furthermore, it is difficult to refine imprinted items due to the fact that there are multiple Variables to worry about, Any or all of this could have a likely effect on the chemical, Properties of the imprinted components in morphological and molecular identification, it is a rapidly emerging technique for the preparation of polymers having unique molecular recognition properties for a given compound MIP synthesis is a relatively easy and inexpensive process, either for its analogues or for a single enantiomer. For the selective extraction of COC and BE from urine samples, newly synthesized molecularly imprinted polymer sorbents were proposed in this report. using a functional monomer which To build a monolithic solid-phase micro extraction (SPME) fiber, Styrene and Allyl chloride are used, as well as Ethylene glycol methacrylate (EGDMA) as a suitable cross-linker and Cocaine as a template. A non-imprinted polymer was created by preparing a polymer without selective binding sites (NIP). All of these analytical procedures were utilized to extract, preconcentrate, and selectively determine Cocaine and its derivatives (SPME) with gas chromatography and mass spectrometry (GC/MS). sturdiness, The manufactured fiber's basic and vital role in SPME is due to its stability and durability. The samples were taken from a suspected cocaine abuser who was donated by the medico-legal directorate (Baghdad, Iraq). The analytes were monitored using a (GC MS), UV-vis, Scanning electron microscopy (SEM), and FTIR. The relative standard deviations (RSD percent ) for two patients' repeated studies for three measurements vary from (1.587-4.545) percent (at 20-100 ppm of Cocaine). Cocaine relative recoveries in human urine samples spiked with the drug are in the range of (102-105).

Біотестування нафтових сорбентів на основі відходів полімерів

Introduction. Biotesting is considered to be an effective method of assessing the potential hazard of chemical, physical or biological effects on an ecosystem. Biotesting is carried out experimentally using, as a rule, standardized laboratory test systems, by recording changes in biologically important indicators (test reactions) under the influence of the studied samples. Hydrobionts act as biologically sensitive sensors: protozoa, algae, crustaceans, mollusks, fish, etc. Biotic indicators can provide information about the transformation of the ecosystem, the state of organisms and the degree of acceptability of influences to preserve the diversity of life forms and their balanced development. During the bioremediation of oil-contaminated water bodies at low temperatures and at high water flow rates (mountain streams) there are significant difficulties and traditional approaches and sorbents can not always be applied. Therefore, it is necessary to develop new non-traditional sorbents. At the same time, it is ecologically expedient to use multi-ton waste of packaging polymeric materials extracted from solid household waste, which are biologically and chemically inert, have unique sorption properties and are suitable for multiple use. Two ecologically dangerous problems have been solved - water pollution by oil products and the growth of polymer packaging in the share of household waste. The goal is to biotest the change of oil-contaminated environment during purification in model conditions with the use of polymer hydrophobic sorbents from raw materials extracted from solid household waste as bioremediators. Research objectives: to establish biological and toxicological safety of the use of secondary polymer raw materials from packaging waste as oil sorbents; to investigate the safety of using environmentally friendly surfactants from vegetable raw materials common in Ukraine to increase the extraction of petroleum products from water. Methods and techniques: toxicological - determination of water toxicity on Daphnia magna acute according to DSTU 4173: 2003 (ISO 6341: 1996, MOD) and chronic according to DSTU 4166: 2003 (ISO 10706: 2000, MOD), photometric method for determining the amount of oil in water according to GOST 17.1.4.01-80. The research results show the effectiveness of hydrophobic polymer sorbents made from secondary polymer raw materials extracted from solid waste in water contaminated with petroleum products to ensure their localization-sorption. The mortality rates of daphnia in all samples with sorbents at the beginning of the experiment were much lower than in the control, because the bulk of the contaminant was adsorbed on the surface of hydrophobic sorbents. At the end of the experiment, the best result in terms of the number of viable daphnia was observed in the cut of a sorbent made of polypropylene, the surface of which is covered with surfactants extracted from Milnyanka medicinal (Saponaria officinalis L). In this sample, the mortality of the test culture is 23%, which is 32% less than the control - 72%. Conclusions. Studies of the impact on aquatic ecosystems and the toxic effect of developed petroleum sorbents on Daphnia magna Straus have established the effectiveness of hydrophobic polymeric sorbent in water contaminated with petroleum products, ensuring their localization-sorption. The mortality rates of daphnia in all studied samples of sorbents except the sorbent from PVC waste were significantly lower than in the control, because the bulk of the contaminant was adsorbed in the polymeric sorbent. Biotesting showed that the sorption material based on polymeric secondary raw materials did not have a toxic effect in the process of purification of water from hydrocarbons. Therefore, it can be considered promising as a basis for bioremediators and for further use in the purification of water bodies from dissolved and spilled petroleum products. However, further in-depth toxicological studies require PVC-based sorbents, although their effects have not gone beyond what is acceptable and it is necessary to study their behavior under the influence of temperature changes and the reaction of other test organisms.

Rapid Diagnosis of Methanol Poisoning with a Handheld Detector

Introduction Over 800 people died this year in Iran alone as a result of methanol poisoning [1]. In fact, such outbreaks are quite common with thousands of victims each year [2]. However, no inexpensive and fast point-of-care method exists for diagnosis of methanol intoxication to rapidly respond to disasters. Currently, methanol poisoning is detected directly through blood analysis by gas chromatography or indirectly through blood gas analysis [3]. Both require trained personnel, are expensive and rarely available in developing countries where most outbreaks occur. Blood methanol levels can also be determined non-invasively in exhaled breath (Figure 1a), analogous to ethanol as widely applied by law enforcement [4]. However, current chemical sensors cannot distinguish methanol from the usually much higher ethanol background in the breath of poisoned victims. Here, we present an inexpensive and handheld detector for rapid and highly selective methanol detection. Method The handheld detector is shown in Figure 1b. It consists of a capillary inlet for sampling from Tedlar bags, a separation column consisting of a packed bed of Tenax TA polymer sorbent to separate the breath mixture [5], a chemoresistive Pd-doped SnO2 microsensor to quantify the methanol and ethanol concentrations, and a rotary vane pump (SP 135 FZ 3 V, Schwarzer Precision, Germany) drawing the sample through the column to the sensor. A microcontroller (Raspberry Pi Zero W, Great Britain) with integrated circuits on a custom-designed printed circuit board (PCB) is used for autonomous sensor heating, film resistance readout, pump flow control as well as wireless communication with a computer or smartphone [6].The detector was validated with methanol-spiked breath of drunken volunteers (0.1% blood ethanol) [7]. Late expiratory breath was sampled into Tedlar bags and subsequently spiked with 10–1000 ppm methanol on a dynamic gas mixing setup to simulate poisoning without intoxicating volunteers. Samples were then measured by the detector and a high resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). Results and Conclusions The main challenge for chemical sensors is the selective detection of breath methanol over high ethanol concentrations present after consumption of contaminated beverages or during methanol poisoning treatment where ethanol is even used as an antidote. The present detector (Figure 1b) achieves this with a compact separation column, where ethanol absorbs stronger (and thus is retained longer) than methanol, analogous to GC. A downstream chemoresistive microsensor based on Pd-doped SnO2 nanoparticles quantifies the methanol and ethanol sequentially with high sensitivity. Figure 1c shows the sensor response to breath (green) after consumption of an alcoholic beverage and when spiked with 23 (blue), 66 (purple) and 148 ppm (red) methanol. These methanol levels correspond to endogenous (0–10 ppm), harmless exogenous (10–52 ppm) and toxic concentrations (>52 ppm), respectively. Most importantly, the sensor detects no significant methanol concentration in the original breath (PTR-TOF-MS, <1 ppm) with sensor response below the LOD, as expected from physiological breath methanol concentrations (median 0.26 ppm), while the spiked concentrations are recognized distinctly at 1.8 min.In total, 105 methanol-spiked breath samples from 20 volunteers after consumption of water, beer, liquor or wine were evaluated and the measured methanol concentrations of the detector and PTR-TOF-MS are shown in Figure 2a. Indicated also are the concentration ranges where antidote (>52 ppm, grey shaded) and hemodialysis (>131 ppm, red shaded) treatments are recommended from the corresponding blood methanol concentrations. The detector shows excellent agreement with PTR-TOF-MS (R2 = 0.966) over the entire concentration range (14–1079 ppm) and in the presence of 0–316 ppm ethanol.As a result, this device is promising to screen methanol poisoning and classify severity. This detector can be equipped with a disposable mouthpiece, as for commercial breath alcohol testers, and readily applied as a point-of-care diagnostic tool for fast screening of methanol poisoning by first responders and clinicians.

Compact Formaldehyde Detector Based on Filter–Sensor System with Validated Performance in Indoor Air

Introduction Formaldehyde is a carcinogenic indoor air pollutant emitted from wood-based furniture, building materials, paints and textiles.[1] Yet, no low-cost sensor exists for on-site monitoring to fulfill stringent current and upcoming (e.g., 8 parts-per-billion by volume, ppb, in France by 2023) exposure guidelines. Here, we present an inexpensive and handheld formaldehyde detector with proven performance in real indoor air. Selectivity is achieved by a compact packed bed column of nanoporous polymer sorbent that separates formaldehyde from interferants present in ambient air. Downstream, a highly sensitive nanoparticle-based chemoresistive Pd-doped SnO2 sensor detects formaldehyde in the relevant concentration range down to 5 ppb within 2 min. Method The handheld formaldehyde detector consists of a separation column and a chemoresistive microsensor [2]. The Separation column consists of a packed bed of Tenax TA powder (500 mg poly(2,6-diphenyl-p-phenylene oxide), 60–80 mesh, ~35 m2 g-1, Sigma-Aldrich) packed inside a Teflon tube (4 mm inner diameters) and secured on both ends with silanized glass wool plugs [3]. The sensor is based on a Pd-doped SnO2 nanoparticle film prepared by flame spray pyrolysis (FSP) and directly deposited onto microsensor substrates [4]. The measurement of emissions from wood products was based on standard testing protocol EN-717-1 to ensure comparable results. Measurements with room air were performed by exposing the detector directly to air from the laboratory. To also test higher concentration, room air was spiked with additional formaldehyde from the gas standard on a dynamic gas mixing setup. Results and Conclusions The concept of the formaldehyde detector is illustrated in Figure 1a–c. Indoor air contains >250 different analytes that are separated by a packed bed separation column of commercial Tenax TA particles. Tenax TA offers a high surface area (25 m2 g-1) due to its macroporous structure (Type II adsorption isotherm, Figure 1d) with a volume-average pore size of 120 nm (inset in Figure 1d). This enables efficient adsorption and retention of analytes, similar to a gas chromatographic column, though much more compact (13 cm length), inexpensive (˂ $20 for the Tenax TA powder) and without the need for column heating. After the column, formaldehyde is detected separately from interferants (e.g., hydrogen, methanol), thus selectively, by a highly sensitive but non-specific chemoresistive microsensor (Figure 1e). It consists of a highly porous film of flame-made and directly deposited Pd-doped SnO2 nanoparticles (Figure 1f) that form fine networks with large surface area (54.5 m2 g-1) for formaldehyde detection down to 5 ppb..We validated this detector on real indoor air samples from our laboratory (Figure 2a). First, it shows a large response from non-retained compounds that might be CH4, CO and H2. These gases are all usually present at hundreds of ppb in indoor air. Thereafter, a smaller peak is detected (SNR >40, see inset) at 107 s corresponding to formaldehyde at 45 ppb according to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). It is not interfered by methanol and ethanol, which are both eluted later, in line with synthetic gas mixtures. Figure 2b shows the scatter plot of the formaldehyde concentration measured by the detector and PTR-TOF-MS for pristine (squares, measured on two different days) and formaldehyde-spiked indoor air (circles) in the range of 14–475 ppb. Both instruments show excellent agreement with an R2 of 0.996, despite the challenging lab environment with high and varying background concentrations of acetone (up to 1,000 ppb) and ethanol (up to 4,000 ppb). Most importantly, the detector shows a low average error of only 10 ppb and can clearly differentiate safe levels from such above the WHO guideline (dashed line) and when immediate sensory irritation (dotted line) occurs.As a result, based on its compact size and low price, this device is promising for monitoring of formaldehyde in indoor air. When interconnected, such next-generation low-cost detectors could enable distributed chemical recognition (Figure 2c) for air quality in “smart” buildings and “future” cities [5].

Polymeric metal-containing ionic liquid sorbent coating for the determination of amines using headspace solid-phase microextraction.

This study describes the design, synthesis, and application of polymeric ionic liquid sorbent coatings featuring nickel metal centers for the determination of volatile and semivolatile amines from water samples using headspace solid-phase microextraction. The examined polymeric ionic liquid (PIL) sorbent coatings were composed of two ionic liquid monomers (tetra(3-vinylimidazolium)nickel bis[(trifluoromethyl)sulfonyl]imide [Ni2+ (VIM)4 ]2[NTf2 - ] and 1-vinyl-3-hexylimidazolium [HVIM+ ][NTf2 - ]), and an ionic liquid cross-linker (1,12-di(3-vinylimidazolium)dodecane [(VIM)2 C12 2+ ]2[NTf2 - ]). With these ionic liquid monomers and cross-linkers, three different types of coatings were prepared: PIL1 based on the neat [Ni2+ (VIM)4 ]2[NTf2 - ] monomer, PIL2 consisting of the [Ni2+ (VIM)4 ]2[NTf2 - ] monomer with addition of cross-linker, and PIL3 composed of the [HVIM+ ][NTf2 - ] monomer and cross-linker. Analytical performance of the prepared sorbent coatings using headspace solid-phase microextraction gas chromatography-mass spectrometry was compared with the polydimethylsiloxane and polyacrylate commercial coatings. The PIL2 sorbent coating yielded the highest enrichment factors ranging from 5500 to over 160000 for the target analytes. The developed headspace solid-phase microextraction gas chromatography-mass spectrometry method was applied for the analysis of real samples (the concentration of amines was 200μg/L), producing relative recovery values in the range of 90.9-120.0% (PIL1) and 83.0-122.7% (PIL2) from tap water, and 84.8-112.4% (PIL1) and 79.2-119.3% (PIL2) from lake water.

Enhanced adsorption of perfluorooctanoic acid using functionalized imidazolium iodide ionic liquid‐based poly (glycidyl methacrylate)

AbstractPer‐ and polyfluoroalkyl substances (PFASs) are among the emerging pollutants of public health and the environment due to environmental persistence, bioaccumulation, and potential toxicity. Removal of PFAS under mild conditions is a challenge. Therefore, employment of organic functionality immobilized on polymeric sorbents has driven significant attention. Herein, new imidazolium‐based ionic liquid (IIL) covalently grafted on poly (glycidyl methacrylate) (PGMA) support was synthesized successfully and characterized by Fourier transform infrared, scanning electron microscope, and thermal gravimetric analysis. The functionalized imidazolium ionic liquid‐based PGMA was applied in perfluorooctanoic acid (PFOA) removal from an aqueous solution. The effect of contact time, adsorbent dose, temperature, pH, and counter anions investigated on the extent of adsorption has been investigated. The concentration of PFOA solutions was measured by ethyl violet active substances assay, and equilibrium data were analyzed by Langmuir, Freundlich and Tempkin isotherms. The experimental results have been fitted to Langmuir model at ambient temperature and the maximum monolayer coverage capacity (qm) was found to be 769.23 mg/g. Also the thermodynamic parameters were obtained, and observed that the adsorption of PFOA onto imidazolium iodide‐PGMA was an endothermic and spontaneous process at the temperatures under investigation.

Reusable organosilicon hybrid sorbents with tunable oil interest via PEG-PPG copolymer

Synthetic polymers having hydrophobic cross-linked structures in order to remove oil spills have been gaining interest in environmental applications. Herein, a series of sorbents were produced by using PEG-b-PPG and PEG-co-PPG triols and organosilane cross-linker via bulk polymerization. The polymer sorbents were characterized by FTIR, thermal gravimetric analysis, scanning electron microscopy (SEM), and their interests towards polar and nonpolar solvents were examined via swelling, absorption-desorption kinetics and reusability tests. Besides, the effect of block-, copolymer-of PEG and PPG triol macromonomer on oil and water absorbency is investigated. The obtained sorbents exhibited high and quick absorption abilities towards organic liquids that were in the range of 5–28 gg-1. Moreover, they can selectively remove the oil from oil/water mixtures and can repeatedly be applied for absorbing oils. The reusability test shows that the polymer sorbents maintained their absorption-desorption loop with no structural change or capacity loss after 10 cycles. These results show the promising potential of the sorbents for the purging of water from oils in environmental applications.

Оцінка ефективності вилучення розчинених у воді нафтопродуктів переробленими відходами полімерної упаковки в середовищі рослинних ПАР

Оцінка ефективності вилучення розчинених у воді нафтопродуктів переробленими відходами полімерної упаковки в середовищі рослинних ПАР

Dual mixed-mode poly (vinylpyridine-co-methacrylic acid-co-ethylene glycol dimethacrylate)-based sorbent for acidic and basic drug extraction from oral fluid samples

In this study, a dual mixed-mode polymer sorbent was prepared via one-step thermally initiated polymerization of 4-vinylpyridine (VP), methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) for the solid-phase extraction (SPE) of basic and acidic drugs. The use of VP and MAA as ionizable functional monomers allowed the tailoring of ion-exchange and hydrophobic features of the polymer. The obtained polymer was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Next, the retention behavior of dual mixed-mode polymer towards basic and acidic drugs was investigated. Moreover, the practical capability of this novel material was tested for the extraction of relevant drugs such as cocaine, 3-methylmethcathinone, and diazepam in oral fluid samples. Recovery values (at different spiked levels in blank oral fluid samples), ranging from 69 to 99%, and limits of detection (LODs), between 0.10 and 0.25 μg L−1, were obtained.

Comparison of two sample preparation methods for 1H-NMR wine profiling: Direct analysis and solid-phase extraction

This study compares two sample preparation methods: direct analysis (DA) and solid-phase extraction (SPE) for wine samples analysis by proton nuclear magnetic resonance (1H-NMR) spectroscopy. For this purpose, the profile of Mexican commercial wines was evaluated. The selected wines were produced with different grape varieties: ('Barbera', 'Nebbiolo', 'Zinfandel', 'Merlot', 'Petite Syrah', 'Cabernet Sauvignon', 'White Zinfandel' and mixture of 'Chenin blanc' and 'Colombard') coming from the principal wine-producing region of Mexico, Baja California State. DA provided faster data acquisition in comparison to SPE and preserved the original sample composition. Using DA-NMR thirty two metabolites were identified, including organic acids, amino acids, sugars, alcohols and phenolic compounds. Furthermore, SPE-NMR using a polymeric sorbent allowed to retain phenolic compounds giving a better picture on the aromatic region and eliminating major polar compounds like water, ethanol and sugars. Fourteen compounds were identified by SPE-NMR including higher alcohols, flavanols and hydroxybenzoates. A control chart for the first principal component allowed to confirm the precision of the SPE-NMR method, while a comparison of the concentration of two metabolites found in both methods was used to evaluate their recovery (20 % for isoamyl alcohol and 78 % for phenethyl alcohol). The information obtained with both methods about the main compounds and phenolic metabolites provides new insights into the metabolomic profile of wine, which could be useful in future targeted studies.

The role of pKa, log P of analytes, and protein matrix in solid-phase extraction using native and coated nanofibrous and microfibrous polymers prepared via meltblowing and combined meltblowing/electrospinning technologies

Effect of physicochemical properties including dissociation constant (pKa) and partition coefficient (log P) of the compounds on their extraction efficiency in sample preparation using fibrous polymer sorbents has been demonstrated. Poly-ε-caprolactone as meltblown/electrospun composite fibers, and polypropylene, polyethylene, poly(3-hydroxybutyrate), poly(lactic acid), and polyamide 6 in the meltblown fiber format were used as sorbents in solid-phase extraction. In addition, the polycaprolactone fibers were coated with dopamine, dopamine combined with heparin, and tannin, respectively, to modify their extraction properties. These fibers that were not yet used for extractions and the unique combination of sorbents and analytes significantly extends the scope of nanofibrous extraction. The extraction efficiency was determined using model pharmaceuticals including acetylsalicylic acid, moxonidine, metoprolol, propranolol, propafenone, diltiazem, atorvastatin, and amiodarone. These model compounds displayed the widest differences in both pKa and log P values. The extraction efficiency of some of the fibers reached 96.64%. Coating of polycaprolactone fibers with dopamine significantly improved extraction efficiency of slightly retained metoprolol while moxonidine was not retained on any sorbent. The fibrous sorbents were also tested for extraction of pharmaceuticals in bovine serum albumin and human serum, respectively, to demonstrate their capability to extract them from a complex protein-containing matrix. The clean-up efficiency of our fibers was compared with that of a commercial restricted access media (RAM) C-18 alkyl-diol silica column. Our technique is in accordance with the requirements of modern sample preparation techniques.

Synthesis of Ion-Imprinted Polymer for Solid-Phase Extraction (IIP-SPE) of Lead from Tap Water Samples before ICP/OES Analysis: Compared to Monte Carlo simulation

In this research, an ion-imprinted polymer (IIP) sorbent for lead ion has been synthesized to selective Pb extraction before the sensitive ICP/OES analysis. For this purpose, the lead complex was fabricated using N-isoacrylamide as a monomer, ethylene glycol dimethacrylate as a crosslinker, and azobutyronitrile azobis as a primer. The product was examined by furrier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The results show that the synthesized IIP has high efficiency in the adsorption of lead ions due to several suitable extraction sites (nitrogen and sulfur atoms) present in the polymer structure. Experimental evidence showed that the highest Pb ion uptake was at pH = 6. Also, 1 M nitric acid solution in a volume of 5 mL has the highest amount of elution. Penetration volume for Pb from IIP-SPE was measured 50 mL. The developed method was finally utilized to analyze Pb in various tap water samples, and the obtained results were compared with the standard method.

Development of terpene based sorbents via emulsion templating: Synthesis and swelling behavior

Polymeric sorbent materials exhibiting excellent swelling capacity were developed using high internal phase emulsion (HIPE) templating approach. Precursor HIPEs were prepared by using continuous phases that composed of mixtures of β-myrcene (monomer) and 1,3-butanediol dimethacrylate (crosslinker). The influence of β-myrcene concentration on the emulsion stability and crosslinking was investigated. Swelling behaviors of resulting polyHIPEs in different solvents were studied. It was found that the maximum swelling capacities were reached 713%, 667% and 310% in benzene, toluene and hexane, respectively.

SILVER(I) PRECONCENTRATION USING m-AMINOPHENOL CONTAINING SORBENT FROM AQUEOUS SOLUTIONS

The influence of sorption characteristics on the removal of silver(I) has been examined. The sorption capacity of chelating polymeric sorbent, based on maleic anhydride styrene copolymer modified with m-aminophenol, towards Ag(I) ions was studied. The pH of sorption was maximum at the value 6. With the increasing of initial metal concentration, sorption of silver(I) increases and reached maxima at val-ue 80∙10-3 M. At the final stage, the elution process of Ag(I) was established and find that HNO3 1 M is the best elution agent. Multiple use of the regenerated sorbent for sorption process is possible. This study shows that using of mentioned sorbent modified with m-aminophenol is effective for removal of silver(I) ions from aqueous solutions

Miniature piezoresistive sensor for detecting volatile organic components

This paper reports a piezoresistive gas sensor, which detects the stress of polymer swollen due to sorption of trace gas molecules. The sensor consists of a Si-polymer composite and a Si cantilever with a piezoresistor at the support. The stress is transformed via the cantilever lateral deflection to the strain at the piezoresistor at the cantilever support. The saturation time for water signal is ca 440 s, and the response is reversible. The response rate, d(∆R/R)/dt, exhibits a maximum at 15.5 s. The ethanol and acetone signals show maxima of lower magnitude. The Fickian diffusion model with variable surface concentration of analyte represents very well the sensor response. The predicted maximum response rate is [d(∆R/R)/dt]max∝Sε∞D1/2b1/2, where S is device sensitivity, ε∞, is equilibrium strain of swollen polymer, D is analyte diffusivity, and b is the rate of change of surface concentration of analyte. The response time corresponding to this maximum is tmax∝1/b. For low humidity, the observed sensitivity is S=2.2. An array of sensors, with properly selected polymer sorbents is expected to function as detector of volatile gas components in human breath and/or in atmosphere.

Porous Polycalix[n]arenes as Environmental Pollutant Removers

A new and innovative class of calixarene-based polymers emerged as adsorbents for a variety of compounds and ions in solution and vapor media. These materials take advantage of the modifiable rims and hydrophobic cavities of the calixarene monomers, in addition to the porous nature of the polymeric matrix. With main-chain calixarenes' function as supramolecular hosts and the polymers' high surface areas, polycalixarenes can effectively encapsulate target analytes. This feature is particularly useful for environmental remediation as dangerous and toxic molecules reversibly bind to the macrocyclic cavity, which facilitates their removal and enables repeated use of the polymeric sorbent. This Spotlight touches on the unique characteristics of the calixarene monomers and discusses the synthetic methods of our reported calixarene-based porous polymers, including Sonogashira-Hagihara coupling, and diazo and imine bond formation. It then discusses the promising applications of these materials in adsorbing dyes, micropollutants, iodine, mercury, paraquat, and perfluorooctanoic acid (PFOA) from water. In most cases, these reports cover materials that outperform others in terms of recyclability, rates of adsorption, or uptake capacities of specific pollutants. Finally, this Spotlight addresses the current challenges and future aspects of utilizing porous polymers in pollution treatment.