Solid-phase Extraction Sorbent Research Articles

Porous Polymer Sorbents in Micro Solid Phase Extraction: Applications, Advantages, and Challenges.

In recent years, porous polymers have gained significant attention for their application as powerful and selective sorbents in micro solid phase extraction (µSPE). In this review we explore the preparation and utilization of various porous polymer sorbents, highlighting their impact on enhancing µSPE techniques. Molecularly imprinted polymers (MIPs), graphene oxide-modified frameworks, and zeolitic imidazole frameworks (ZIFs) are among the innovative materials discussed. These innovative materials have significantly improved µSPE methods, offering enhanced extraction efficiencies, superior selectivity, and reduced solvent consumption, all of which align with the principles of green chemistry. Key findings of this review include the demonstration that MIPs exhibit excellent target specificity, making them ideal for complex matrices, while graphene oxide frameworks and ZIFs provide increased surface area and stability for diverse analytical applications. Despite these advancements, challenges remain, particularly the high cost of certain innovative materials, limited reusability, and the absence of automation in µSPE workflows. Furthermore, controlling the precise synthesis and functionalization of these sorbents continues to be a limiting factor. To address these issues, future research should focus on developing cost-effectiveness methods, the use of biopolymer or sustainable feedstocks, and scalable synthesis methods; integrating automation into µSPE; and exploring new polymeric materials with enhanced properties. Additionally, novel hybrid materials that combine the strengths of multiple sorbents offer a promising direction for future exploration. We critically analyze the advantages and limitations of each sorbent type, providing a comprehensive overview of their applications in µSPE. This paper also examines the synthesis, characterization, and unique properties of these porous polymers, emphasizing their role in advancing analytical chemistry towards more efficient and environmentally friendly practices. The need for continued development of high-performance, low-cost, and sustainable sorbents is underscored to further enhance the effectiveness of µSPE techniques.

Optimization, Validation, and Application of Cleanup-Coupled Liquid Chromatography-Tandem Mass Spectrometry for the Simultaneous Analyses of 35 Mycotoxins and Their Derivatives in Cereals.

Mycotoxins occur singly or as co-contaminants and are primarily present in carbohydrate-rich foods such as cereals and cereal-based products. To effectively monitor mycotoxin co-contamination in cereals and cereal-based products, the simultaneous analysis of mycotoxins and their derivatives is required. Therefore, we coupled cleanup with LC-MS/MS for the rapid and robust quantitation of 35 analytes in wheat samples, including ergot alkaloids (EAs), which are rarely included in such analyses. To investigate the effects of different mycotoxin types on adsorbents, various dispersive solid-phase extraction sorbents were evaluated; a C18 end-capped sorbent exhibited the most effective cleanup performance. The method was validated by analyzing samples fortified with the mycotoxins at three concentration levels. The results exhibited high linearity, high recoveries, and repeatability. The methodology was applied for commercial cereal samples. The cereal samples were found to be 74% contaminated, and two samples measured levels of EAs at 609.63 μg/kg and 294.93 μg/kg, exceeding the limits defined by the EU for rye milling products. These findings highlight the validity of our novel method and the necessity of continuously monitoring mycotoxin levels in cereals to ensure food safety.

Effect of various culinary treatments on the glycoalkaloid content of potato peel

Potatoes are one of the most consumed foods worldwide. During germination, glycoalkaloids (GAs) with potential bioactive properties are produced, which, at high concentrations, may have adverse health effects. Potato peels, a byproduct generated in large quantities but increasingly used in contemporary cuisine, contain significant levels of these GAs. This paper examines GA levels in potato peels after various culinary treatments (boiling, steaming, baking, air frying, conventional deep frying, and double frying) to provide new data and ensure food safety. An optimized extraction method using ultrasound-assisted extraction (UAE) was employed, followed by purification with mesostructured SBA-15 silica functionalized with octadecylsilane (C18) chains as sorbent in solid-phase extraction, prior to HPLC-DAD determination of α-solanine and α-chaconine levels in the samples. The method was validated, obtaining excellent recovery values (88 – 96 %) and low detection and quantification limits (0.3 and 1 mg/L, respectively). Upon application of the validated analytical method to the samples culinarily treated using the most common cooking techniques (boiling, steaming, baking, air frying, conventional deep frying, and double frying) at various times and temperatures, the obtained results demonstrated significant reductions (between 52 % and 84 %) in GAs content in the treated potato peels, compared to fresh samples. Statically significant degradation of these compounds was observed through baking at elevated times and temperatures (74 – 84 %), as well as both conventional deep frying and double frying (76 – 83 %).

Design of magnetically functionalized hydrogen-bonded organic framework for extraction and enrichment of bisphenols from environmental and human samples

The magnetic functionalized hydrogen bond organic framework named Fe3O4@PFC-11/1 was prepared for the first time and used as sorbent of magnetic solid-phase extraction to enrich bisphenols (BPs) prior to high-performance liquid chromatography analysis. The limits of detection were achieved 0.03–0.07 ng/mL, and the enrichment factors were calculated in the range of 234–296. The adsorption of Fe3O4@PFC-11/1 to BPs can be finished within 10 s. The maximum adsorption capacities of Fe3O4@PFC-11/1 to bisphenol F, bisphenol A, bisphenol B and bisphenol AF were calculated as 249.95, 413.74, 474.38 and 676.06 mg/g, respectively. The main adsorption mechanisms of BPs on Fe3O4@PFC-11/1 are attributed to pore filling, van der Waals force, hydrogen bond and π-π interaction. Finally, BPs were successfully detected in environmental and human samples with satisfactory recoveries (78.2–117.9 %). This work presented combination of Fe3O4 with PFC-1 to obtain a promising magnetic sorbent for extraction and enrichment of trace compounds in complex matrices.

Development of a Non-Covalent Molecularly Imprinted Polymer via Precipitation Method for the Selective Separation of D-Xylose From Sugarcane Residues.

The agro-industry generates substantial waste, necessitating eco-friendly solutions. This study introduces a novel molecularly imprinted polymer (MIPs) for the selective separation of D-xylose from sugarcane residues. A non-covalent imprinted polymer was synthesized via precipitation and optimized through D-xylose adsorption assays. The polymer demonstrated an Imprinting Factor of 3.34, adsorption equilibrium within 30min, notable reusability retaining over 95% of its adsorption capacity after three cycles, and high selectivity coefficients (α>2.00) for all saccharides tested. The adsorption isotherm followed the Langmuir model. Characterization confirmed successful imprinting, with the imprinted polymer exhibiting a surface area of 69.4m2/g and pore volume of 0.26cm3/g, compared to 8.7m2/g and 0.03cm3/g for the non-imprinted polymer. D-xylose separation was tested using hemicellulosic hydrolysate from sugarcane straw and bagasse. The polymer applied as a sorbent in dispersive solid-phase extraction with the hydrolysate achieved 90.29±1.27% D-xylose adsorption. Desorption in pure water recovered 81.48±1.22% of the adsorbed D-xylose. This method advances separation techniques, offering an efficient solution for sample pre-treatment and expanding the application of MIPs.

Surfactant-modified carbon nano-onion-β-cyclodextrin nanocomposite as an efficient sorbent in dispersive solid phase extraction of metoprolol and atenolol from plasma samples prior to HPLC–PDA analysis

Surfactant-modified carbon nano-onion-β-cyclodextrin nanocomposite as an efficient sorbent in dispersive solid phase extraction of metoprolol and atenolol from plasma samples prior to HPLC–PDA analysis

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.

Ultrasound-assisted continuous flow synthesis of natural phenolic-coated Fe3O4 for magnetic solid phase extraction of tetracycline residues in honey

Waste rubber bark abundant in phenolics can be used to produce an adsorbent for the enrichment and determination of tetracycline. Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) coated with naturally extracted phenolics from waste rubber bark were synthesized for the first time by ultrasound combined with a continuous flow approach. The production of Fe3O4 MNPs with effective contact surface areas (45.3 m2 g−1) was employed as a novel attractive sorbent in magnetic solid phase extraction (MSPE) to selectively preconcentrate oxytetracycline, tetracycline, chlortetracycline, and doxycycline before HPLC-UV analysis. This MSPE-HPLC exhibited wide linear ranges (14.0–260.0 μg kg−1), with low limits of detection (10.0 μg kg−1) and quantitation (14.0–20.0 μg kg−1), and was successfully applied to quantify tetracycline residues in honey samples, with recoveries ranging from 81.3 % to 117.9 %. This method offers a potential alternative for determining tetracycline in food with a high enrichment factor, high precision, and more effective accuracy, selectivity, and sensitivity.

Pharmacokinetics of pulmonary indacaterol in rat lung using molecular imprinting solid-phase extraction coupled with RP-UPLC

Indacaterol, a β2 agonist prescribed for long-term management of patients with chronic obstructive pulmonary disease and asthma. In this study the first MISPE cartridges was developed using indacaterol as a template for its selective extraction from rat lung tissues, enabling precise pharmacokinetic evaluation at the drug’s site of action. A molecular imprinting polymer was synthesized using indacaterol as a template, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linker with a molar ratio (1: 4: 20). The polymer was characterized by a high binding capacity of 9840 ± 0.86 and high selectivity with an imprinting factor of 4.53 ± 0.12. The synthesized polymer was utilized as a sorbent in solid-phase extraction to purify and extract indacaterol from lung tissue matrix. The optimum molecularly imprinted solid-phase extraction (MISPE) conditions were 20.0 mg of molecular imprinting polymer and non-imprinting polymer, acetonitrile as the loading solvent, acetonitrile: water (20: 80; by volume) as the washing solvent, and methanol: acetic acid (90: 10; by volume) as the eluting solvent. A pharmacokinetic study was performed for indacaterol in rat lungs using the synthesized and optimized MISPE cartridge as a tool for sample purification. These parameters were determined in the lung tissues of rats emphasizing the local exposure of indacaterol to its target organ. The Cmax and Tmax were 51.020 ± 2.810 µg mL− 1 and 0.083 ± 0.001 h, respectively. The AUC 0−24 and AUC0 − inf were 175.920 ± 1.053 and 542.000 ± 5.245 µg h mL− 1, respectively. The elimination rate constant was 0.014 ± 0.00012 h− 1 and the half-life time was 48.510 ± 0.012 h. This study successfully developed and optimized MISPE cartridges using indacaterol as a template, enabling precise pharmacokinetic evaluation in rat lung tissues. The cartridges demonstrated high binding capacity and selectivity, providing crucial insights into the local exposure of indacaterol at its site of action.

Preparation of Restricted Access Media-Methacrylic Resin and Its Application as the Sorbent of Solid-Phase Extraction in the Lamotrigine Determination in Human Plasma by HPLC–UV

Preparation of Restricted Access Media-Methacrylic Resin and Its Application as the Sorbent of Solid-Phase Extraction in the Lamotrigine Determination in Human Plasma by HPLC–UV

Core-shell polymer microspheres with strong cation-exchange character for the extraction of basic pharmaceuticals from aqueous samples

The application of core-shell materials as packing materials for liquid chromatography columns is common in analytical chemistry, however their use as sorbents in solid-phase extraction (SPE) is surprisingly underexplored. In the present study, core-shell polymer microspheres with strong cation-exchange character were designed and synthesized. These new materials benefit from having hypercrosslinked and relatively thin functional shells, which raises the specific surface areas and sorption capacities of the sorbents and allows for relatively shorter diffusion path lengths for analytes.The core-shell polymer microspheres were evaluated as SPE sorbents for the extraction of basic pharmaceuticals from environmental water samples. Following optimization of the pH and volume of the loading solution, as well as optimization of the loading step, the SPE method was validated in terms of apparent and relative recoveries, matrix effect, limits of detection and quantification and precision. The method yielded very promising results in terms of apparent recoveries (>39 %) and matrix effect (<±29 %) and was applied successfully to the determination of basic pharmaceuticals in environmental water samples (river water, effluent wastewater and influent wastewater).

Systematic Comparison of Extract Clean-Up with Currently Used Sorbents for Dispersive Solid-Phase Extraction

Dispersive solid-phase extraction (dSPE) is a crucial step for multiresidue analysis used to remove matrix components from extracts. This purification prevents contamination of instrumental equipment and improves method selectivity, sensitivity, and reproducibility. Therefore, a clean-up step is recommended, but an over-purified extract can lead to analyte loss due to adsorption to the sorbent. This study provides a systematic comparison of the advantages and disadvantages of the well-established dSPE sorbents PSA, GCB, and C18 and the novel dSPE sorbents chitin, chitosan, multi-walled carbon nanotube (MWCNT), and Z-Sep® (zirconium-based sorbent). They were tested regarding their clean-up capacity by visual inspection, UV, and GC-MS measurements. The recovery rates of 98 analytes, including pesticides, active pharmaceutical ingredients, and emerging environmental pollutants with a broad range of physicochemical properties, were determined by GC-MS/MS. Experiments were performed with five different matrices, commonly used in food analysis (spinach, orange, avocado, salmon, and bovine liver). Overall, Z-Sep® was the best sorbent regarding clean-up capacity, reducing matrix components to the greatest extent with a median of 50% in UV and GC-MS measurements, while MWCNTs had the largest impact on analyte recovery, with 14 analytes showing recoveries below 70%. PSA showed the best performance overall.

A guidance for the enrichment of micropollutants from wastewater by solid-phase extraction before bioanalytical assessment

BackgroundWastewater can contain a complex mixture of organic micropollutants, with both chemical analysis and effect-based methods needed to identify relevant micropollutants and detect mixture effects. Solid-phase extraction (SPE) is commonly used to enrich micropollutants prior to analysis. While the recovery and stability of individual micropollutants by SPE has been well studied, few studies have optimized SPE for effect-based methods. The aim of the current study was to develop and evaluate two standard operating procedures (SOPs) for the enrichment of micropollutants in preparation for chemical analysis and bioanalysis, one covering a broad range of chemicals and the other selective for estrogenic chemicals.ResultsPristine surface water spiked with > 600 micropollutants was used to develop a generic extraction method for micropollutants with a wide range of physiochemical properties, while water spiked with estrogenic chemicals was used to identify a selective extraction method. Three different SPE sorbents were tested, with recoveries of individual chemicals and effect in assays indicative of mutagenicity, estrogenic activity, and fish embryo toxicity assessed. The sorbent HRX at pH 7 was selected for the generic extraction method as it showed the best recovery of both individual chemicals and effect in the bioassays. The sorbent HLB at pH 3 showed optimal recovery of estrogenic chemicals and estrogenic activity. The two optimal SPE methods were applied to spiked and unspiked wastewater effluents, with the concentrations of detected chemicals and observed effects similar to those of previous studies. The long-term storage of both extracts and SPE cartridges for estrogens and estrogenic activity after extraction with the HRX and HLB methods were evaluated, with estrogenic effectiveness close to 100% after 112 days when HLB was used.ConclusionsHRX is recommended for generic extraction, while HLB is optimal for the selective extraction of estrogenic micropollutants. However, if a laboratory only wants to use a single SPE sorbent, HLB can be used for both generic and selective extraction as it yielded similar chemical and effect recovery as HRX for a wide range of micropollutants. This paper is supplemented by the final SOP that includes a variant for generic extraction and one for the extraction of estrogenic chemicals.

The use of a hypromellose based sorbent for a solid-phase extraction in the quantitative determination of procaine in combination drugs

Aim – to assess the selectivity and metrological characteristics of the spectrophotometric method for procaine determination in combination drugs using a solid-phase extraction sorbent based on hypromellose. Material and methods. The solid-phase extraction sorbent was obtained with hypromellose and ethyl cyanoacrylate; the procaine hydrochloride and sodium hydroxide formed the active centers. The sorbent was prepared using a standard method. The sorption capacity of the obtained sorbent samples for procaine was 10.2 ± 1.0 µg/g. For the study, we selected the combination drugs containing procaine and its salts, such as "Menovazin", "Sulfocamphocaine", and "Otolorin". The eluate optical density was registered using a SF-56 spectrophotometer (OKB SPECTR LLC) at an analytical wavelength of 292 nm in a cuvette with an optical layer thickness of 1 cm. The reference solution was a 0.1 M hydrochloric acid solution. To calculate the procaine content in the eluates, a calibration graph (dependence of eluate optical density on procaine concentration) was plotted in the concentration range of 1–20 mcg/ml. To evaluate the selectivity (specificity) of sample preparation in chromatographic separation of the combination drugs, the absorption spectra were registered in the wavelength range of 200–400 nm for eluates obtained using purified water and a 0.1 M hydrochloric acid solution. The procaine and benzocaine were identified in the eluate by the presence of absorption maxima at wavelengths of 222 and 286 nm for benzocaine, and 228 and 292 nm for procaine. For statistical processing of the experimental results and determination of metrological characteristics of the analysis method, we followed the GPM.1.1.0013 "Statistical processing of results of physical, physicochemical, and chemical tests". Results. We have demonstrated the selectivity of the spectrophotometric determination of procaine in certain combination drugs using a solid-phase extraction sorbent based on hypromellose. The selective binding of the analyzed substance with active centers in the sorbent and stepwise elution with purified water and a 0.1 M hydrochloric acid solution during solid-phase extraction eliminated the interfering effect of drug components during the UV-spectrophotometry of procaine. The use of a hypromellose based sorbent improved the metrological characteristics and reduced the systematic error of the quantitative determination method by an average of 14.4%. The proposed methodological approach using a selective sorbent might be recommended as the quality control for combination drugs containing procaine and its salts.

Synthesis and application of magnetic graphene oxide covalent organic framework composite for extraction of anabolic androgenic steroids and β-agonists in animal urine and tissue samples

In this work, a magnetic graphene oxide covalent organic framework composite was synthesized and utilized as an effective sorbent for magnetic solid phase extraction. A comprehensive investigation was conducted to optimize the extraction conditions, including sample pH, sample volume, adsorbent amount, adsorption time, choice of elution solution, elution volume, elution time, and ionic strength. Subsequently, the developed extraction method was combined with liquid chromatography-tandem mass spectrometry for the detection of 7 anabolic androgenic steroids and 4 β-agonists. Under the optimized condition, the limits of detection for the 7 anabolic androgenic steroids and 4 β-agonists ranged from 0.5 to 2 ng L−1, with relative standard deviations varying from 4.18 % to 12.4 % at a concentration of 0.025 μg L−1. Calibration curves were established using the peak area of analytes at concentrations spanning 5–500 ng L−1, resulting in correlation coefficients within the range of 0.9949–0.9989. The enrichment factors achieved through magnetic solid phase extraction were found to be 91.4–97.3. The proposed method was successfully applied for the determination of target analytes in hog urine, bovine urine, beef, mutton, pig liver and pork powder samples. Ractopamine and clenbuterol were identified in the pork powder (quality control sample) at concentrations of 21.0 μg kg−1 and 42.6 μg kg−1, respectively. The proposed method is a sensitive, reliable, and convenient analytical method for anabolic androgenic steroids and β-agonists monitoring in animal urine and tissues.

Direct Determination of Glyphosate and Its Metabolites in Foods of Animal Origin by Liquid Chromatography-Tandem Mass Spectrometry.

Glyphosate is the most used herbicide in agriculture. Its major metabolite is AMPA (aminomethylphosphonic acid), but N-acetyl-AMPA and N-acetylglyphosate are also metabolites of interest. For risk assessment, a general residue definition was proposed as the sum of glyphosate, AMPA, N-acetyl-glyphosate and N-acetyl-AMPA, expressed as glyphosate. A confirmatory method for glyphosate in fat, liver and kidneys, as well as a confirmatory method for AMPA and N-acetyl-glyphosate in all matrices, are still missing. In this paper, we present a method for the quantitative determination of glyphosate residues and its metabolites AMPA, N-acetyl-AMPA and N-acetyl-glyphosate by liquid chromatography-mass spectrometry (LC-MS/MS) in adipose tissue, liver, eggs, milk and honey without derivatization. Different chromatographic columns were tested, with the Hypercarb column providing the best results. The analytes were eluted with mobile phases of acidified water with 1.2% formic acid and 0.5% formic acid in acetonitrile. Sample purification procedures were also optimized by varying the solvent extraction mixtures (water, methanol and mixture ψ (methanol, water) = 1:1, each with the addition of 1% formic acid (v/v)), using different sorbents in solid phase extraction (SPE) (polymeric cationic (PCX) and anionic (PAX)) and using dispersive solid phase extraction (dSPE) (C18 and PSA) by modifying the extraction procedures. Finally, the analytes were extracted from the samples with 1% formic acid in water (v/v). Milk and adipose tissue were purified by the addition of dichloromethane, while liver and egg samples were purified by SPE with a mixed cation exchange sorbent and ultrafiltration with cut-off filters. The proposed analytical procedures were validated according to SANTE/11312/2021 guidelines: linearity, limits of quantification, precision and accuracy were determined for all matrices. The limits of quantification (LOQs) ranged from 0.025 to 0.2 mg kg-1. Precision, expressed as relative standard deviation, was <20%, while accuracy, expressed as analytical recovery, ranged from 70% to 120%. During method validation, the measurement uncertainty was estimated to be <50% for all analytes. Good validation parameters according to the SANTE document were achieved for all analytes. Therefore, the method can be considered reliable and sensitive enough for routine monitoring of polar pesticides. The application of the accredited method in routine analysis will provide data that are useful for the re-evaluation of risk assessment studies in foods of animal origin.

Construction of PCN-222@PCN-134 as sorbent of dispersive solid-phase extraction for extraction and enrichment of sulphonamides

A MOF-on-MOF composite (PCN-222@PCN-134) was synthesized by seed epitaxial growth method and applied as sorbent to extract sulfonamides (SAs) in different sample matrices. Using PCN-222@PCN-134 as sorbent, a dispersive solid-phase extraction was developed to clean-up and preconcentration of SAs prior to HPLC-DAD analysis. The linear range of the method are achieved between 0.1 and 200 ng/mL, and the limits of detection are in the range of 0.03–0.27 ng/mL. Comparison with pristine MOFs, the performance of PCN-222@PCN-134 composite is significantly improved. The enrichment factors are obtained in the range of 254–333. The adsorption kinetics and adsorption isotherms are in accordance with pseudo-second-order and Langmuir models, respectively. The spiked recovery of real samples including egg and urine are between 76.4 and 120.1 % with relative standard deviation not higher than 12.1 %. After 14 times of use, the recovery rate of sorbent to SAs is still above 80 %. This work demonstrates that PCN-222@PCN-134 possesses excellent extraction performance to SAs, which can be used to clean-up and preconcentration of trace SAs in different sample matrices, such as egg and urine.

Core-shell magnetic covalent organic polymer nanocomposites as an adsorbent for the extraction of flavonoids.

A novel 3D magnetic nanocompositematerialbased on covalent organic polymers was successfully synthesized and utilized as an efficient sorbent for magnetic solid-phase extraction. It exhibited a regular core-shell structure, large specific surface area, superior stability, and paramagnetism. To evaluate its extraction efficiency, six flavonoids were tested, demonstrating maximum adsorption capacities ranging from 90 to 218mg/g. Additionally, the material exhibited remarkable reusability and mechanical stability, maintaining its original state over eight cycles with consistent recovery. An analytical strategy combining magnetic solid-phase extraction with high performance liquid chromatography and tandem mass spectrometry was developed for the determination of flavonoids in orange, honey, soybean, and Dioscorea bulbifera L. samples. The low limits of detection (0.01-0.1ng/mL) and limits ofquantification (0.05-0.5ng/mL), as well as satisfactory recovery (80.4-114.8%), were obtained. The linear range started from the limits of quantification to 500ng/mL with R2 ≥ 0.9929. These results suggest that the prepared adsorbent possesses excellent adsorption capabilities for flavonoids, highlighting its significant potential for detecting these compounds in complex sample matrices.

Fast and efficient extraction and determination of nonsteroidal anti-inflammatory drugs using poly(8-hydroxyquinoline)-coated magnetic graphene oxide nanocomposite prior to capillary electrophoresis analysis in wastewater, breast milk, and urine samples.

In this study, magnetic graphene oxide coated with poly(8-hydroxyquinoline) was successfully synthesized, characterized, and utilized as a novel sorbent for the ultrasonic-assisted dispersive magnetic solid-phase extraction of naproxen and ibuprofen. These analytes served as representative analytes for two nonsteroidal anti-inflammatory drugs in various real samples. Characterization techniques, such as IR, X-ray powder diffraction, field emission scanning electron microscopy, energy-dispersive X-ray-mapping, and Brunauer-Emmett-Teller (BET), were used to confirm the correctness synthesis and preparation of the nanocomposites. Effective parameters on the extraction efficiency were investigated to maximize the analytical performance of the developed method. The dynamic range (1-1000µgL-1), coefficients of determination (R2≥0.997), the limits of detection (0.3-1.0µgL-1), and limit of quantification (1.0-3.0µgL-1), intra-day and inter-day precisions (3.5%-7.2%) were achieved. The method validation results showed extraction recovery ranging from 80.4% to 96.0% and preconcentration factors ranging from 137 to 140.

Sustainable magnetic covalent organic framework materials for multi-residue analysis of pyrethroid pesticides in tobacco, fruits and vegetables

Magnetic covalent organic frameworks (MCOFs) materials were synthesized in deep eutectic solvents (DESs) instead of traditional toxic organic solvents under ambient conditions. The reaction time could be reduced to about 3 h, which was more than 12 h for the traditional synthesis method. Materials characterization indicated that the MCOFs materials with Tp and BD as monomer synthesized in ChCl-urea based DESs (i.e. Urea-MTpBD) showed good magnetic property and higher specific surface area. The Urea-MTpBD materials were used as a magnetic solid phase extraction (MSPE) sorbent for the enrichment and determination of 16 pyrethroid pesticides (PYs), coupled with GC-MS/MS technology. The effective enrichment of PYs with Urea-MTpBD materials was achieved, which was due to the synergistic effects of π-π stacking and hydrophobic interactions. The limits of detection (LODs) of 16 PYs with the developed method ranged from 2.15 to 5.67 ng/mL, while the recovery was between 70.99 % and 109.09 % with excellent intra-day and inter-day precisions (RSDintra ≤ 5.78 %, RSDinter ≤ 9.13 %). The developed method was applied successfully to determine 16 PYs in tobacco, fruits and vegetables. Furthermore, the Urea-MTpBD materials could be reused three times, which showed not only highly efficient, but also economical and sustainable.