Magnetic Solid Phase Extraction Technique Research Articles

Accurate prediction bioaccessibility of PAHs in soil-earthworm system by novel magnetic solid phase extraction technique

Conventional chemical extraction methods may lead to overestimate or underestimate bioaccessibility due to their inability to provide realistic kinetic information regarding PAHs in soils. In this study, we propose the use of magnetic solid phase extraction (MSPE) technique for assessing the bioaccessibility of PAHs in the soil-earthworm system. Firstly, a novel polydopamine-coated magnetic core-shell microspheres (Fe3O4–C16@PDA) was developed by a one-pot sol-gel and self-polymerization method. The PDA coatings not only enhance the hydrophilicity of material surfaces but also exhibit excellent biocompatibility. The maximum adsorption capacity of Fe3O4–C16@PDA for 16 PAHs was 52.72 mg g−1, indicating that the proposed material fulfills the assessment requirements for highly contaminated soil. To compare the measurement of PAHs and their uptake by earthworms (Eisenia fetida), experiments were conducted using four different soils with varying properties. The desorption kinetics data obtained from these experiments demonstrated that the capability of the MSPE in accurately predicting the bioavailable portions of PAHs. After a 28-day exposure, the best predictor of bioavailable PAHs in earthworms was MSPE method exhibited the highest correlation coefficient (R2 > 0.90), and its slopes in the four soils were 0.972, 0.961, 1.012, and 0.962, respectively, all close to 1. These results demonstrate that the MSPE method successfully mimics the conditions encountered in soil-earthworm systems and effectively assess bioaccessibility of PAHs in soils.

Magnetic Solid Phase Extraction for Determination of Dyes in Food and Water Samples

Recently, magnetic solid-phase extraction (MSPE) is an important technology due to its use in analytical chemistry, biotechnology, and medicinal fields. MSPE shows rapid isolation of target analyte from large volume samples, the huge surface area of magnetic nanoparticles (MNPs), and simplicity in application due to using an external magnetic field instead of using packing column, centrifuge and filter papers. The aim of this review is to evaluate the extraction and determination of dyes in food and water samples by using the MSPE technique.

The drug interaction potential of berberine hydrochloride when co-administered with simvastatin, fenofibrate, gemfibrozil, metformin, glimepiride, nateglinide, pioglitazone and sitagliptin in beagles

Berberine (BBR) hydrochloride is a traditional Chinese medicine with unique hypoglycemic and lipid-lowering effects discovered in recent years. The combination of BBR with other hypoglycemic drugs and lipid-lowering drugs could become a promising treatment strategy. With the aim of evaluating the potential drug-drug interaction (DDI) based on the pharmacokinetics between BBR and simvastatin, fenofibrate, gemfibrozil, metformin, glimepiride, nateglinide, pioglitazone and sitagliptin in beagles, an UPLC-MS/MS method has been developed and validated. The analytes and internal standards were extracted from plasma samples using a magnetic solid phase extraction technique, and then separated by a Luna® Omega C 18 column (20.0 × 2.0 mm, 1.6 μm) with water containing 3 mM ammonium and 0.1% formic acid and acetonitrile containing 3 mM ammonium and 0.1% formic acid as the mobile phase. Validation of the UPLC-MS/MS method was carried out following the criteria of the Chinese Pharmacopeia, mainly including specificity, carryover, calibration curve, crosstalk, precision, accuracy, dilution integrity, matrix effect, recovery and stability. The results showed that all the criteria of the method validation met the Chinese Pharmacopoeia guidelines, and the proposed UPLC-MS/MS method was proven to be sensitive, simple and specific to determine all the analytes in the beagles’ plasma samples simultaneously. Meanwhile, the potential DDI between BBR and simvastatin, fenofibrate, gemfibrozil, metformin, glimepiride, nateglinide, pioglitazone and sitagliptin was confirmed in this paper, especially for simvastatin, fenofibrate, gemfibrozil and glimepiride.

Ternary magnetic Fe3O4@C3N4@covalent organic framework for facile extraction and determination of organophosphorus pesticides in fruit

In this study, a magnetic composite material was prepared based on covalent organic framework (COFs) materials for the detection of trace organophosphorus pesticides. Fe3O4@C3N4@COFs were synthesized by a layer-by-layer assembly strategy and applied to the selective identification, detection and removal of profenofos pesticides using magnetic solid-phase extraction technique. After seven regeneration cycles, the composite exhibited excellent selectivity and affinity for profenofos, and eventually still achieved an extraction efficiency higher than 75%. Under optimized conditions, the proposed magnetic solid-phase extraction method coupled with high-performance liquid chromatography-tandem mass spectrometry showed a low limit of detection (1 × 10−5 μg/mL) for profenofos. The developed method was successfully used to detect profenofos in spiked fruit samples with satisfactory recoveries (74.33% −116.59%) and relative standard deviations (0.27% −7.41%). This study highlights the potential of COFs-based magnetic composites in sample pretreatment for targeted analysis and is a novel pathway for efficient sample preparation in food safety analysis.

Development and validation of an UPLC-MS/MS method for simultaneous determination of fifteen targeted anti-cancer drugs in human plasma and its application in therapeutic drug monitoring

In this study, an ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously detect 15 targeted anti-cancer drugs: aletinib, afatinib, apatinib, icotinib, dasatinib, erlotinib, gefitinib, crizotinib, lapatinib, regorafenib, ceritinib, sorafenib, vemurafenib, imatinib, and N-desmethyl imatinib. Plasma samples were processed using a new magnetic solid phase extraction technique to extract each drug. The 15 analytes and four isotope internal standards were separated using an Agilent Eclipse XDB-C18 column (50.0 × 2.1 mm, 1.7 µm) with water containing 0.1% formic acid and acetonitrile as the mobile phase. The method verification included specificity, calibration curves, carryover, accuracy, crosstalk, precision, stability, recovery, dilution integrity, and matrix effects. The results showed that the developed UPLC-MS/MS method met the requirements of the U.S. Food and Drug Administration guidelines for methodological validation and could be used to monitor plasma concentrations. The response function was established for concentration range of 2.5–2500.0 ng/mL for aletinib, afatinib, apatinib, icotinib, dasatinib, crizotinib, regorafenib, vemurafenib, and N-desmethyl imatinib and 10.0–10,000.0 ng/mL for erlotinib, ceritinib, imatinib, sorafenib, gefitinib, and lapatinib, with a coeffificient of correlation of > 0.9977 for all the compounds. The precision and accuracy of all the analytes were < 6.88% and 5.29%, respectively. The percentage recovery and matrix effect of all the analytes were 91.3–103% and 93.8–102% for three QC concentrations levels. The recovery and matrix effect for all the ISs ranged from 93.7% to 98.8% and 94.6–101%. Meanwhile, we also found that the plasma concentrations of these targeted anti-cancer drugs showed large individual differences, which is not conducive to the treatment of tumors. Therefore, therapeutic drug monitoring (TDM) of these 15 targeted anti-cancer drugs is necessary, and this method could be used for TDM and exploration of pharmacokinetics of the aforementioned 15 targeted anti-cancer drugs.

Development and Validation of an UPLC-MS/MS Method for Simultaneous Determination of Fifteen Targeted Anti-Cancer Drugs in Human Plasma and Its Application in Therapeutic Drug Monitoring

In this study, an ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously detect 15 targeted anti-cancer drugs: aletinib, afatinib, apatinib, icotinib, dasatinib, erlotinib, gefitinib, crizotinib, lapatinib, regorafenib, ceritinib, sorafenib, vemurafenib, imatinib, and N-desmethyl imatinib. Plasma samples were processed using a new magnetic solid phase extraction technique to extract each drug. The 15 analytes and four isotope internal standards were separated using an Agilent Eclipse XDB-C18 column (50.0 × 2.1 mm, 1.7 μm) with water containing 0.1% formic acid and acetonitrile as the mobile phase. The method verification included specificity, calibration curves, carryover, accuracy, crosstalk, precision, stability, recovery, dilution integrity, and matrix effects. The results showed that the developed UPLC-MS/MS method met the requirements of the U.S. Food and Drug Administration guidelines for methodological validation and could be used to monitor plasma concentrations. Meanwhile, we also found that the plasma concentrations of these targeted anti-cancer drugs showed large individual differences, which is not conducive to the treatment of tumors. Therefore, therapeutic drug monitoring of these 15 targeted anti-cancer drugs is necessary to improve the efficacy and reduce the side effects of cancer treatment.

Magnetic Solid-Phase Extraction Based on Poly 4-Vinyl Pyridine for HPLC-FLD Analysis of Naproxen in Urine Samples.

A magnetic solid phase extraction technique followed by liquid chromatography with a fluorescence detector for naproxen analysis in human urine samples was developed. The method includes the extraction of naproxen with a magnetic solid synthetized with magnetite and poly 4-vinylpriridine, followed by the magnetic separation of the solid phase and desorption of the analyte with methanol. Under optimal conditions, the linear range of the calibration curve was 0.05–0.60 μg L−1, with a limit of detection of 0.02 μg L−1. In all cases values of repeatability were lower than 5.0% with recoveries of 99.4 ± 1.3%. Precision and accuracy values are adequate for naproxen (Npx) analysis in urine samples.

Efficient development of a magnetic molecularly imprinted polymer for selective determination of trimethoprim and sulfamethoxazole in milk

A molecularly imprinted polymer was synthesized on the surface of magnetic nanoparticles for subsequent application in the extraction of trimethoprim (TMT) and sulfamethoxazole (SMX) residues in bovine milk. The magnetic polymer was suitably characterized and demonstrated high stability and optimum adsorption capacity under the conditions of analysis. MMIP was used in the preparation of milk samples by the magnetic solid phase extraction technique whose optimized parameters were: sample volume, elution solvent and its volume, amount of adsorbent, stirring time, and pH of the sample. The relative recoveries of analytes were 98.66 ± 5.59% and 75.57 ± 0.72% for TMT and SMX, respectively. The method developed was linear in the range of concentration of 0.05–20 µg mL−1 with correlation coefficients of 0.997 and 0.994 for TMT and SMX, respectively. It was also demonstrated satisfactory accuracy and precision, as well as adequate robustness and good drugs stability in the matrix. The method was applied satisfactorily in real milk samples contaminated with residues of these antibiotics.

Magnetic adsorbent based on mesoporous silica nanoparticles for magnetic solid phase extraction of pyrethroid pesticides in water samples

Mesoporous KIT-6-magnetite composite (Fe3O4@SiO2@KIT-6) was successfully prepared and characterized by transmission electron microscopy, scan electron microscopy, elemental mapping, energy dispersive X-ray spectrum, Fourier transform infrared spectroscopy, thermal gravimetric analysis, X-ray powder diffraction, Brunauer Emmett Teller analysis and magnetic property analysis. It was then applied as adsorbent for magnetic solid phase extraction of fenpropathrin, lambda-cyhalothrin, S-fenvalerate and bifenthrin from water samples before analyzed by high performance liquid chromatography-ultraviolet detector. A few factors impacting extraction were studied. The optimal results were acquired by using acetonitrile to eluent the targets adsorbed on 40 mg of Fe3O4@SiO2@KIT-6 adsorbent in 100 mL water samples at a pH of 7 at 25 ℃ within 10 min. The experimental limit of detections of fenpropathrin, cyhalothrin, S-fenvalerate and bifenthrin are 0.01 × 10−3, 0.006 × 10−3, 0.01 × 10−3 and 0.005 × 10−3 mg∙L-1, respectively. Good relative recoveries (86.58–98.80%) and reproducibility values are also obtained. The kinetic experiment shows that the adsorption follows pseudo-second order, while the isotherm experiment follows Langmuir isotherm model. Trace pyrethroid pesticides in water samples can be detected by the developed magnetic solid phase extraction technique followed by high performance liquid chromatography, which is simple, easy, environmental friendly and efficient.

Providing hyper-branched dendrimer conjugated with β-cyclodextrin based on magnetic nanoparticles for the separation of methylprednisolone acetate

This study introduced a developed approach for dendritic β-cyclodextrin (β-CD) in order to obtain high sorption capacity. Synthetic strategy exploits the reactivity between acrylic acid and allyl glycidyl ether for high-yielding assembly via grafting on to the magnetic nanoparticles that are modified using 3-mercaptopropyltrimethoxysilane for various building branches and host–guest molecules of β-CD. The methodology has been applied for the preparation of a series of β-CD conjugated magnetic nanoparticles with dendrimers as a nano-sorbent for the extraction of methylprednisolone acetate. This study allowed us to probe (i) the effects of the dendric-cyclodextrin architecture on the affinity of sorption capacity, (ii) the drug influence between the cyclodextrin core and the polyester dendrimer, and (iii) the result of sorbent formation for using the anti-inflammatory drug as a target guest into the ring of β-CD on biological extraction. It was found that the adsorption behavior could be fitted by the Langmuir adsorption isotherm model. The adsorption capacity of MPA is found to be 12.4 mg g−1 and indicated the homogeneous sites onto polymer grafted magnetite nano-sorbent surface. Our results confirm the high capability of this type of dendrimer-β-CD for drug extraction in biological fluids and pharmaceutical samples. This nano-sorbent assists the magnetic solid phase extraction technique represented in the high extraction yield (up to 97%) for methylprednisolone acetate in biological human fluids and pharmaceutical samples. Moreover, the achieved polymeric nano-sorbent of the reaction combination was facilitated by a magnetic field and reusability was performed without any notable loss in the sorbent activity.

Comparative study of pyrethroids residue in fruit peels and fleshes using polystyrene-coated magnetic nanoparticles based clean-up techniques

An efficient and rapid method for quantifying pyrethroids pesticide residue in fruits samples was developed in the present study. The application of lab prepared polystyrene magnetic nanoparticles based magnetic solid phase extraction technique combined with liquid-solid extraction helped clean-up the sample and preconcentrate the targeted analytes prior to HPLC quantification. The lab prepared nanoparticles were characterised with Fourier transform infrared spectroscopy, atomic force microscopy, X-ray diffraction spectroscopy, as well as vibrating sample magnetometer to study their size, morphology, crystal structure, functional groups and magnetism properties, respectively. Afterwards, optimisation of the parameters affecting extraction efficiency was carried out in order to achieve optimum conditions for extracting pyrethroids residue from fruit samples. Analytical performances were evaluated by carrying out experiments at optimum conditions. Results showed that the limit of detection and limit of quantification were below 0.1445 and 0.5116 ng g−1, respectively for the six pyrethroids tested. The recovery rates were within the range of 73.6%–123.1% with intra-day and inter-day relative standard deviation being less than 16.5% and 15.4%, respectively, suggesting satisfactory reproducibility of the proposed method. Real sample analysis was performed using 6 kinds of commonly consumed fruits obtained from local supermarkets in Singapore, including apples, pears, oranges, lemons, grapes and nectarines. The peel and flesh were tested separately to study the difference of pyrethroids residue in different parts of fruits. The grape sample tested was detected with permethrin residue on its peel. There was no violation since the permethrin amount detected was way much lower than the maximum residue limit set by local government.

Investigation of mesoporous carbon materials by magnetic solid phase extraction of selected phthalates from water samples

In the present work ordered mesoporous carbon materials soft templating-acidic (STA) were applied as adsorbents in magnetic solid phase extraction technique for isolation of selected phthalates fro...

Magnetic micro-/nano-materials: functionalization and their applications in pretreatment for food samples

Magnetic solid phase extraction technique, based on functional magnetic materials, is currently a hot topic in the separation and analysis of complex samples. This paper reviews the reported methods for the functionalization of magnetic micro-/nano-materials, such as sur- face grafting organic groups, coating carbon or inorganic oxide, grafting or coating polymer, being loaded to the surface or pores of supports, being introduced into the skeleton of sup- ports, and physically co-mixing methods. Moreover, we briefly introduce the applications of the functional magnetic micro-/nano-materials in pretreatment for food samples.