Commercial Solid-phase Extraction Research Articles

Comparative Analysis of Pharmaceutical Persistence in Canadian Wastewater Treatment Plants Utilizing Molecularly Imprinted Polymers and Commercial Solid Phase Extraction Sorbents

In this study, the performances of a synthesized Molecularly Imprinted Polymer (MIP) and a commercial Solid Phase Extraction (SPE) cartridge were compared in terms of the removal efficiency and quantification of pharmaceutical compounds in wastewater samples. Concentration analysis of Emtricitabine, Tenofovir, Naproxen, Diclofenac, Ibuprofen, and Efavirenz was conducted in influent, primary effluent, secondary effluent, and post-chlorination water samples using liquid chromatography-UV detection. Regressions analysis revealed high linearity (R2 values from 0.9980 to 0.9999) for the compounds, alongside recoveries ranging from 90.9% to 100%. The method detection limits (MDLs) were also determined. Removal efficiencies were computed, with Naproxen and Ibuprofen demonstrating complete removal (100%), while other compounds displayed different of removal efficiency levels. The MIP was found to perform slightly better than traditional SPE cartridges in terms of selectivity, efficiency, and overall performance. This study provides valuable insights into the concentrations of target compounds at various treatment stages, emphasizing the importance of choosing extraction cartridges in wastewater treatment processes.

Cyano-functionalized porous hyper-crosslinked cationic polymers for efficient preconcentration and detection of phenolic endocrine disruptors in fresh water and fish

Sensitively analyzing phenolic endocrine-disrupting chemicals (EDCs) in environmental substrates and aquatic organisms provides a significant challenge. Here, we developed a novel porous hyper-crosslinked ionic polymer bearing cyano groups (CN-HIP) as adsorbent for the highly efficient solid phase extraction (SPE) of phenolic EDCs in water and fish. The CN-HIP gave an excellent adsorption capability for targeted EDCs over a wide pH range, and the adsorption capacity was superior to that of several common commercial SPE adsorbents. The coexistence of electrostatic forces, hydrogen bond, and π-π interactions was confirmed as the main adsorption mechanism. A sensitive quantitative method was established by coupling CN-HIP based SPE method with high-performance liquid chromatography for the simultaneously determining trace bisphenol A, bisphenol F, bisphenol B and 4-tert-butylphenol in fresh water and fish. The method afforded lower detection limits (S/N = 3) (at 0.03–0.10 ng mL−1 for water and 0.8–4.0 ng g−1 for fish), high accuracy (the recovery of spiked sample at 88.0%–112 %) and high precision (the relative standard deviation < 8.5 %). This work provides a feasible method for detecting phenolic EDCs, and also opens a new perspective in developing functionalized cationic adsorbent.

For the occurrence of PPCPs from source to tap: A novel approach modified in terms of sample preservation and SPE cartridge to monitor PPCPs in our water supply

BackgroundThe ongoing infusion of pharmaceutical and personal care products (PPCPs) into ecosystems sustains a perpetual life cycle and leads to multi-generational exposures. Limited understanding of their environmental impact and their intrinsic ability to induce physiological effect in humans, even at low doses, pose great risks to human health. Few scholarly works have conducted systematic research into the occurrence of PPCPs within potable water systems. Concurrently, the associated monitoring techniques have not been comprehensively examined with regards to the specific nature of drinking water, namely whether the significant presence of disinfectants may influence the detection of PPCPs. ResultsA modified approach in terms of detailed investigation of sample preservation and optimization of an in-lab fabricated solid phase extraction (SPE) cartridge filled with DVB-VP and PS-DVB sorbent was proposed. Favorable methodological parameters were achieved, with correlation coefficients spanning from 0.9866 to 0.9998. The LODs of the PPCPs fluctuated from 0.001 to 2 μg L−1, while the LOQs varied from 0.002 to 5 μg L−1. The analysis of spiked samples disclosed a methodological precision of 2.31–9.86 % and a recovery of 52.4–119 %. We utilized the established method for analyzing 14 water samples of three categories (source water, finished water and tap water) from five centralized water supply plants. A total of 24 categories encompassing 72 PPCPs were detected, with the concentrations of PPCPs manifested a marked decrease from source water to finished water and finally to tap water. SignificanceOur research meticulously examined the enhancement and purification effects of widely used commercial SPE cartridges and suggested the use of in-lab fabricated SPE cartridges packed with DVB-VP and PS-DVB adsorbents. We also conducted a systematic evaluation of the need to incorporate ascorbic acid and sodium thiosulfate as preservatives for PPCP measurement, in consideration of the unique characteristics of drinking water matrices, specifically, the significant concentration levels of disinfectants. Furthermore, the proposed method was effectively employed to study the presence of PPCPs in source water, finished water, and tap water collected from centralized water supply plants.

Facile preparation of sulfonated covalent triazine frameworks for effectively detection of six carcinogenic aromatic amines in cigarette smoke

FDA reported a HPHCs (Harmful and Potentially Harmful Constituents) list for tobacco products and tobacco smoke in 2012, which contained six carcinogenic aromatic amines (AAs). In this work, a sulfonated covalent triazine frameworks (CTF-SO3H) material was synthesized and used as a solid phase extraction (SPE) absorbent for highly effective enrichment and determination of six carcinogenic AAs in cigarette mainstream smoke (MSS), coupled with HPLC-MS/MS technique. The CTF-SO3H material was prepared with a rapid and facile method, which was superior to the general methods. The characterization with Nitrogen adsorption and desorption isotherm experiment, High resolution transmission electron microscopy (HTEM), etc, indicated that the CTF-SO3H material possessed sulfonic acid groups and abundant microporous structure. And the CTF-SO3H material showed good enrichment effect for AAs due to the synergistic effect of π-π stacking and electrostatic interactions. Limits of detection (LODs) of 6 AAs with the developed method were in the range of 0.01–0.11 ng cig−1. Recoveries of 6 AAs were between 80.40% and 106.00%, while the intra-day and inter-day precisions were good (i.e. RSDintra ≤ 6.40%, RSDinter ≤ 9.90%). Commercial cigarette MSS samples were analyzed with the developed method, and a commercial cation exchange SPE column was chosen for comparison. Results obtained by two methods showed a good consistency. However, the CTF-SO3H material needed less dosage, even could be reused for 4 times. Thus, the developed method not only showed high enrichment efficiency, but also was economical.

Speciation and determination of inorganic antimony in tea infusion by using solid-phase extraction-based liquid chromatography-inductively coupled plasma-mass spectrometry

In this work, we developed a method to separate and detect inorganic antimony (iSb) in tea infusions based on liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). Considering that iSb was present in tea infusions in trace amounts, a commercial solid-phase extraction (SPE) column was employed to enrich iSb(III) and iSb(V). In this study, we found that iSb exists in tea infusions in a bound state with an unknown substance rather than in a free state. Therefore, the enrichment step was combined with oxidation and reduction processes. Because of the enrichment process and the high sensitivity of LC-ICP-MS, the LODs of iSb(III) and iSb(V) were both as low as 0.03 μg L−1. The RSDs (n = 6) of iSb(III) and iSb(V) were all below 8.1%, and the recoveries (n = 6) were 92–96% and 90–94%, respectively. Then, a total of six tea infusion samples were inspected. The data revealed that the total Sb in the tea infusions ranged from 0.22 to 0.97 μg L−1, and we found that 50–83% of the total Sb in the tea infusion was iSb. This method is worth promoting since it has satisfying methodological performance.

Preparation of Amphiphilic Solid Phase Extraction Material and Its Application in Aqueous Steroid Hormones Extraction

The steroid hormones have attracted increasing attentions in aquatic environment because of their endocrine disrupting effects at trace concentrations. In this work, amphiphilic solid phase extraction material of divinylbenzene-N-vinyl-2-pyrrolidinone polymer microsphere was synthesized by free radical polymerization. The adsorption of 4 steroid hormones in aqueous solution by prepared amphiphilic microsphere was determined by high-performance liquid chromatography-tandem mass spectrometry method. When methyl cellulose and sodium dodecyl sulfonate were used as dispersants, 2,2’-azobis(2-methylpropionitrile) was used as initiator, the amphiphilic microsphere was successfully prepared at 80 °C for 6 h. The amphiphilic microsphere has high specific surface area of 774 m2 g−1 with uniform particle size, which is comparable to the commercial solid phase extraction fillers. The amphiphilic microsphere has been successfully applied to the enrichment and detection of 4 steroid hormones (17α-hydroxyprogesterone, metandienone, norethindrone and boldenone) in natural water. The recoveries of 4 steroid hormones ranged from 83.7 % to 114 %, and the limit of detection were in the range of 0.70–13.5 ng L−1.

Preparation of chemically modified cellulose filter paper for extracting amphetamine-type stimulants from water followed by HPLC-MS/MS determination

A novel chemically modified cellulose filter paper (CMCFP) was prepared by a two-step reaction of esterification and thiol-ene click reaction with cellulose filter paper (CFP). The paper based CMCFP extraction material was used to extract amphetamine-type stimulants (ATSs) from water, followed by high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS) determination. The FT-IR, XPS, and SEM characterizations showed that the modifiers of 3-mercaptopropionic acid and sodium 4-vinylbenzenesulfonate were successfully covalently grafted onto the CFP. The recovery rates of the 7 target ATSs by CMCFP extraction had a maximum value in the pH range of 4.0–7.0. The kinetic experiments indicated that the main adsorption mechanism of CMCFP for ATSs was chemisorption. The adsorption capacity was greater than 37 ng·cm-2. Surface water and wastewater spike experiments revealed that the determination of 7 ATSs by CMCFP extraction coupled with HPLC-MS/MS method had recoveries of 80.5–116%. Meanwhile, the detection limits were 0.40–3.03 ng·L-1, and the linear range was 20–1000 ng·L-1 with relative standard deviations of 2.2–11%. The CMCFP extraction material obtained in this study is environmentally friendly and economical, and has the same good extraction efficiency as the commercial solid phase extraction cartridges.

Study of degradation of norfloxacin antibiotic and their intermediates by natural solar photolysis.

In this work, the photolysis of the antibiotic norfloxacin (NOR) and the formation of its photodegradation products were studied using UV and solar radiation. Their extraction was also assessed in Milli-Q water and secondary effluents from a wastewater treatment plant. The photolysis of NOR was chromatographically monitored. The structure of each degradation product is related to the reaction of NOR with reactive oxygen species (ROS), as confirmed using radical quenchers and mass spectrometry. Additionally, the feasibility of extracting NOR and its degradation products was assessed using a commercial solid phase extraction system. Photolysis results showed the formation of five degradation products, generated under exposure to both types of radiation. The decays in NOR concentrations for the solar and UV treatments were adjusted to pseudo first-order kinetics with apparent constant values of ksolar = 1.19 × 10-3s-1 and kUV = 3.84 × 10-5s-1. Furthermore, the superoxide radical was the main participant species in the formation of the degradation products P3, P4, and P5. Species P1 and P2 do not need this radical for their formation. The presence of NOR in water opens the possibility of its photolysis by solar radiation. This work contributes to the understanding of the mechanisms that mediate its photodegradation, in addition to studying potential options for its determination and its photodegradation products in the sample treatment.

Sugarcane bagasse as low-cost solid-phase extraction sorbent for pesticides in water

ABSTRACT Effective recycling of organic residues contributes to solving energy crisis and resource recycling. In Egypt, sugarcane is considered one of the most produced agricultural product, which in terms leads to the production of a vast amount of its by-products. In this work, for the first time, untreated sugarcane bagasse (SCB) was utilised as a sorbent in the solid-phase extraction (SPE) of selected pesticides including chlorfenvinphos, chlorpyrifos, diazinon, ethion, profenofos (organophosphorus compounds) and cyprodinil (anilinopyrimidine) from water. Optimal parameters influencing the recovery of the studied pesticides including eluting solvent (type, volume and pH), amount of sorbent and water pH were adjusted. Method performance criteria using SCB cartridges were compared with that of commercial SPE cartridges, indicating SCB as an effective and green chemistry alternative. The final SPE procedure can be briefly described as follows: the SCB (500 mg) SPE cartridge was conditioned with 5 mL methanol followed by 5 mL distilled water. Then, 500 mL water sample (DIW) was loaded on the SCB SPE cartridge. Afterwards, the cartridge was dried using nitrogen for 15 min. Then, 4 mL acetonitrile containing 5% formic acid was used as the eluting solvent to be analysed using LC-MS/MS. The method was validated in accordance with (SANTE/2020/12830 and Eurachem Second Edition 2014). Rapid adsorption and desorption performance for SCB was confirmed by using adsorption kinetic and isotherm studies. Finally, five environmental water samples were analysed using the developed method, only one sample had positive result (profenofos 0.01 µg/L), which is below the accepted limits.

Comparison of solid-phase extraction methods for efficient purification of phosphopeptides with low sample amounts

Efficient phosphoproteomic analysis of small amounts of biological samples (e.g. tissue biopsies) requires carefully selected enrichment and purification steps prior to the nanoflow HPLC-MS/MS analysis. Solid-phase extraction (SPE) is one of the most commonly used approaches for sample preparation. Several stationary phases are available for peptide SPE purification, however, most of the published methods are not optimized to provide good recoveries of phosphorylated peptides. Our goal was to investigate the performance of 13 self-packed and 3 commercial centrifugal SPE cartridges/spin tips, thus enhancing the efficiency of the phosphoproteomic analysis of small amounts of complex protein mixtures. Eight reversed-phase (RP), five graphite, two ion-exchange, and one hydrophilic-lipophilic balance (HLB) stationary phase were evaluated. Two RP, one graphite, and the HLB self-packed centrifugal SPE tips provided excellent results for the purification of 1 µg tissue and cell line digests. Using these methods, the sample loss was significantly reduced compared to one of the commercial SPE methods, 22-58% more unique phosphopeptides were identified, and the recovery was higher by 132-155%.

Miniaturized 3D printed solid-phase extraction cartridges with integrated porous frits

Here we have studied the effect of the thickness and printing orientation using PolyJet 3D printing to fabricate single-material cartridges with built-in porous frits enabling solid-phase extraction (SPE) by packing commercial sorbents. This is achieved by tuning the degree of interpenetration of the building material and the water-soluble support material used in PolyJet 3D printing by modifying the orientation of the print head respective to the frit. SPE cartridges printed at an orientation of 30° with a 150 μm thick integrated frit were selected for the SPE experiments in a compromise between frit permeability to flow and stability to retain commercial sorbents for SPE.The performance of the 3D printed cartridges was evaluated for the SPE of the endocrine-disrupting phenols 4-tert-octylphenol (4-tOP) and 4-nonylphenol (4-NP), comparing three commercial SPE sorbents (Evolute Express ABN, Bond Elut PPL, and Silica-C18). The best overall extraction performance was obtained using Silica-C18, and the main extraction parameters were optimized. Detection limits of 0.3 μg L−1 for 4-tOP and 1.1 μg L−1 for 4-NP were achieved using HPLC-DAD for analyte separation and quantification. Enrichment factors of 30.1 (4-tOP) and 16.2 (4-NP) were obtained under the selected conditions. The developed method was applied to water and milk powder samples obtaining satisfactory recoveries ranging from 97% to 103%. These results demonstrate the suitability of PolyJet 3D printing for the fabrication of miniaturized cartridges with integrated frits for SPE applications.

Use of Sugar Cane Bagasse as Solid Extraction Phase Sorbent to Analyze Hormones from Industrial Effluent

Sugar cane bagasse (SCB) is an abundant byproduct of sugar and bioethanol mills. It has been effectively used as a low-cost biosorbent to remove hazardous chemical compounds from a variety of effluent sources. Herein, we report on the preparation of SCB and its use as a solid phase extraction (SPE) sorbent to retain synthetic hormones (ethinylestradiol, drospirenone, and levonorgestrel) from industrial pharmaceutical plant effluent samples prior to LC–MS/MS quantitative analysis. We evaluated the reproducibility and recoveries and accuracy data analyses were compared with that of commercial SPE (cSPE) cartridges. The results from the evaluated parameters indicated that the SCB bed had an efficiency of >99%, comparable to that of cSPE cartridges, demonstrating the applicability and feasibility of this material as an effective and green chemistry alternative, as well as its biosorbent potential to remove hormones from industrial pharmaceutical effluent.

Development of organic-diffusive gradients in thin films technique for measuring freely dissolved concentrations of tetracyclines using a commercial SPE packing

The freely dissolved concentrations (FDCs) of pollutants are related to their bioavailability in the environment, and the diffusive gradients in thin films technique (DGT) can obtain the FDC of an analyte. Aiming for the detection of the FDCs of tetracyclines (TCs), we used a polyacrylamide hydrogel comprising acrylamide and acrylaide agarose cross-linker as diffusive and binding gels, and a commercial solid-phase extraction (SPE) packing, namely polymer sorbent (PLS), as an adsorption material in the binding gel for the preparation of the organic-diffusive gradients in thin films (o-DGT) devices. The results showed that the diffusion coefficients of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) in the diffusive gels were 1.08 × 10−6, 1.08 × 10−6 and 1.03 × 10−6 cm2/ s at 25 °C, respectively. The binding gel showed excellent performance with adsorption capacities of 534.88–569.42 µg/disc for TC, 527.18–565.98 µg/disc for OTC and 1320.12–1320.86 µg/disc for CTC, respectively. The uptake efficiencies were 94.21–111.12, 71.25–88.44 and 76.10–86.62% for TC, OTC and CTC, respectively, with the TCs concentration of 0.05–10 mg/L. The adsorption kinetics of TCs could be described with a pseudo-second-order model (POSM, R2 >0.97). According to the result of adsorption kinetics, the adsorption rate of TCs in the binding gel was not as fast as that of heavy metals, suggesting that the TCs concentrations at the boundary of binding gels in the o-DGT devices could not decrease to zero. After correction of the boundary concentration, the FDCs accounted for 30.30–56.90, 48.10–64.68 and 16.55–50.16% for TC, OTC and CTC, respectively, while their concentrations ranged from 0.2 to 10.0 mg/L. Our results suggested that SPE packing might be an ideal adsorption material for o-DGT binding gels, and that adsorption kinetics should be corrected when calculating the FDCs of organic pollutants.

3DG Functionalized Magnetic Solid Phase Extraction Materials for the Efficient Enrichment of Hexamethylenetetramine in Vermicelli.

Solid phase extraction (SPE) is regarded as the most effective purification method for complex matrix samples owing to its simplicity of operator, time-saving, high accuracy, and environmental friendliness. SPE technology is still affected by the high cost of commercial SPE columns and poor adsorption selectivity. Hence, the development of low-cost and highly selective adsorbents is quite challenging and demanding in SPE. In this study, a novel 3DG functionalized magnetic solid phase extraction materials was prepared based on “thiol-ene” click chemistry. The structure, morphology, thermal stability, and magnetic properties of the magnetic composites were studied by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Then the adsorption performance of composite was determined by static adsorption experiments, which showed fast binding kinetics (100 min) and good adsorption performance (Qe = 65.34 mg/g). Moreover, these magnetic nanoparticles were used as adsorbents for magnetic solid phase extraction (MSPE) and coupled with high-performance liquid chromatography (HPLC) for separation and detection of illegally added hexamethylenetetramine in vermicelli. As for practical application, the recoveries for the spiked samples in the concentration range of 8–40 μg/g were between 83.24–92.69%, and the RSD was between 0.20–2.07%.

Dummy molecularly imprinted polymers for class-selective extraction of amphetamine-type stimulants from alcoholic and nonalcoholic beverages

Molecularly imprinted polymer was constructed for the first time through dummy imprinting strategy with homopiperonylamine as dummy template. The prepared dummy molecularly imprinted polymer (DMIP) showed high class selectivity towards the most popular amphetamine-type stimulants (ATSs) such as methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxy-amphetamine, and 3,4-methylenedioxy-N-ethylamphetamine with the imprinting factors of 2.280∼3.698 and selectivity factors of 1.654∼3.698. Moreover, ATSs could be rapidly adsorbed from water with the equilibrium time within 5 min. Hydrogen-bonding interaction between the amino groups of ATSs and carboxy on DMIP could be dominated adsorption mechanism. DMIP was employed as solid phase extraction (SPE) sorbents. Under the optimum extraction conditions, the method using DMIP-based SPE and high performance liquid chromatography–tandem mass spectrometry showed good linearity in the range of 0.025∼1.00 μmol L−1, good repeatability (RSD 4.8∼8.6%, n = 5) and low limits of quantification (0.007∼0.200 ng mL−1, S/N = 10). Satisfactory recoveries (72.5∼120%) with low RSD values (<10%) were obtained for all targets viz. spiked coke carbonated drinks, beer and cocktail. Compared with other commercial SPE sorbents, DMIP exhibited lower matrix effect (ME) for coke, beer and cocktail with ME values of 101∼124%, 75.8∼80.2% and 103∼128%, respectively. The obtained results suggested that the developed DMIP materials could be a potential candidate for pretreatment of ATSs in alcoholic and nonalcoholic beverages.

Porous electrospun microfibers for low flow-resistant solid phase extraction of fluoroquinolones in tap water, egg and milk samples

In this work, porous electrospun microfibers (PEMFs) were prepared using a polyimide/polyvinylpyrrolidone/polyethylene glycol (PI/PVP/PEG) solution mixture with coaxial ultrasonic water vapor spraying. After removing PVP and PEG by ultrasonic water washing, the PEMFs were successfully demonstrated as adsorbents for solid phase extraction (SPE). Most non-porous electrospun nanofibers are hundreds of nanometers in diameter, with a specific surface area of dozens of square meters per gram. In contrast, the diameter of the as-prepared PEMFs was tuned between 3 and 8μm, the specific surface area was 76 m2g-1 and the pore size was ca 25nm. Therefore, the flow resistance of the PEMF-SPE cartridges was similar to those of conventional commercial SPE cartridges, and much lower than those of SPE cartridges packed with electrospun nanofibers. Using the PEMF-SPE cartridges with ultra-performance liquid chromatography-fluorescence detector (UPLC-FLD), five fluoroquinolones (FQs) in tap water, egg and milk samples were extracted and quantified successfully. After optimizing the extraction conditions, FQs in water samples were extracted and eluted with high recoveries of 84.8-114.8%. The inter-batch and intra-batch relative standard deviation (RSD) values for the FQs were in the range of 1.9-9.5% (n=3), and the limits of detection were between 0.0024-0.014μg L-1. The method was linear in the concentration range of 0.005-10μg L-1. The reliability of the developed method was validated by analyzing tap water, egg and milk samples, and the recovery values were found to be in the range of 74.8-116.6% under the optimized conditions.

Determination of Phthalate Esters in Beverages and Water Samples by Solid Phase Extraction with Resin Based COFs as Filler

Resin based covalent organic framework material was used as filler for solid phase extraction (SPE), and the solid phase extraction effect was compared with that of traditional COF material (TpBD COFs). The enrichment capacity of four phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate) in beverage samples was investigated by SPE. Adsorption experiments showed that the kinetic adsorption behavior of COF materials for phthalate esters (PAEs) was more consistent with the quasi-second-order kinetic adsorption model, and the static adsorption behavior is more in line with the Freundlich isothermal adsorption model. Solid phase extraction experiments proved that the SPE column prepared with two COF materials as adsorbents had good adsorption effects, high recovery (water: 97.99–100.56% and beverage: 97.93–100.23%) and were reusable (50 cycles), which could meet the requirements for trace detection of phthalate ester. It was found that the solid phase extraction effect was better than the four types of commercial SPE columns. The new COF material reduced the cost of monomer use and provided the possibility for its industrial production. Meanwhile, it also provided a new feasible scheme for enriching trace phthalate esters in practical samples.

An integrated approach for the efficient separation of specialty compounds from biomass of the marine microalgae Amphidinium carterae

An amphidinol-prioritized fractioning approach was for the first time developed to isolate multiple specialty metabolites such as amphidinols, carotenoids and fatty acids using the biomass of the marine microalgae Amphidinium carterae. The biomass was produced in a raceway photobioreactor and the exhausted culture media were reused, thus fulfilling sustainability criteria employing a circular economy concept. The integrated bioactive compounds-targeted approach presented here consisted of four steps with which recovery percentages of carotenoids, fatty acids and amphidinols of 97%, 82% and 99 %, respectively, were achieved. The proposed process was proved to be a better extraction system for this microalga than another based on a sequential gradient partition with water and four water-immiscible organic solvents (hexane, carbon tetrachloride, dichloromethane and n-butanol). The proposed process could be scaled-up as a commercial solid-phase extraction technology well-established for industrial bioprocesses.

Surface imprinted polymer on a metal-organic framework for rapid and highly selective adsorption of sulfamethoxazole in environmental samples

The demand for the removal of pollutants in aqueous solution has triggered extensive studies to optimize the performance of adsorbents, but the adsorption rate and selectivity of adsorbents have been overlooked. Hierarchically ordered porous vinyl-functionalized UIO-66 was used as supporter to prepare a surface molecular imprinted polymer (MIP-IL@UIO-66). The UIO-66 with large specific surface area significantly increased the number of active site of polymer, and so the MIP-IL@UIO-66 can achieve the rapid and highly selective adsorption of sulfamethoxazole (SMZ) in water. The structure and morphology of MIP-IL@UIO-66 was examined using scanning electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms, thermogravimetry, X-ray photoelectron spectroscopy, and X-ray powder diffraction. Results indicate that the presented MIP-IL@UIO-66 has an ultrafast equilibrium rate (equilibrium time, 10 min), large adsorption capability (maximum capacity, 284.66 mg g−1), excellent adsorption selectivity (selectivity coefficient, 11.36), and good reusability (number of cycles, 5 times) via equilibrium adsorption experiments. Subsequently, as a novel solid phase extraction (SPE) adsorbent, the adsorption performance of SMZ onto MIP-IL@UIO-66 was better than that of a commercial SPE adsorbent. A MISPE column combined with high-performance liquid chromatography (HPLC) was presented to detect SMZ in water, soil, egg, and pork samples with recoveries of 91–106%. Hydrogen bonds, electrostatic and π-π interactions, and molecular memory were attributed to recognizing the SMZ of MIP-IL@UIO-66.

Simultaneous determination of amitriptyline, nortriptyline, and clomipramine in aqueous samples using selective multi-template molecularly imprinted polymers

Molecularly imprinted polymers have gained attention as an efficient sorbent media to remove organic contaminants from diverse environmental matrices. In this research endeavor, multi-template molecularly imprinted polymer (mt-MIP) was synthesized and utilized in solid phase extraction (SPE) as a sorption medium for trace analysis of three tricyclic antidepressants (TCAs) (i.e. nortriptyline (NOR), amitriptyline (AMI), and clomipramine (CLO)) by high performance liquid chromatography-photodiode array detector (HPLC-PDA). Physicochemical properties of the synthesized sorbent were assessed by relevant spectroscopic and microscopic techniques to decipher their structural characteristics. mt-MIP with porous texture, cracks, and crevices on the external surface exhibit higher efficacy in extracting the target TCAs due to the enhanced tendency towards sorbate-sorbent interactions. The sorptive extraction of the mt-MIP was explored in standard and real samples (ground water, river water, hospital wastewater, and sewage water sample). mt-MIP integrated SPE technique coupled with HPLC-PDA exhibited linearity (R2 > 0.999) in the concentration ranging from 0.1 to 10 ng/mL with high precision (RSD% < 5) and accuracy (±3%). The developed method lower the detection limits for target TCAs to 0.016–0.029 ng/mL and provided good extraction efficiencies of 97.99 to 99.89%. The proposed mt-MIP-SPE-HPLC method offered high selectivity and sensitivity towards NOR, AMI, and CLO compared with the commercial C18-based SPE method. The spent mt-MIP was successfully regenerable (e.g., up to 8 cycles). The outcomes of the present work successfully revealed the apparent superiority of the mt-MIP towards the practical removal of target TCAs under real world conditions.