Magnetic Polymer Nanocomposites Research Articles

Analysis of 15 bile acids in human plasma based on C18 functionalized magnetic organic polymer nanocomposite coupled with liquid chromatography-tandem mass spectrometry

Because of the “enterohepatic circulation” of bile acid, liver damage can be reflected by monitoring the content of bile acid in the serum of the organism. To monitor the concentration of 15 bile acids in plasma samples, a new technique of PRiME (process, ruggedness, improvement, matrix effect, ease of use) pass-through cleanup procedure combined with high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS/MS) was developed. The sorbent used in the PRiME pass-through cleanup procedure is a new type of magnetic organic resin composite nano-material modified by C18 (C18-PS-DVB-GMA-Fe3O4), which has high cleanup efficiency of plasma samples. It also shows good performance in the separation and analysis of 15 kinds of bile acids. Under the optimal conditions, the results show higher cleanup efficiency of C18-PS-DVB-GMA-Fe3O4 with recoveries in the range of 82.1–115 %. The limit of quantitative (LOQs) of 15 bile acids were in the range of 0.033 µg/L-0.19 µg/L, and the RSD values of 15 bile acids were in the range of 3.00–11.9 %. Validation results on linearity, specificity, accuracy and precision, as well as on the application to analysis of 15 bile acids in 100 human plasma samples demonstrate the applicability to clinical studies.

Eco-friendly UV-spectrophotometric methods employing magnetic nano-composite polymer for the extraction and analysis of sexual boosters in adulterated food products: Application of computer-aided design.

Solid phase extraction (SPE) techniques based on computationally designed magnetic-based multi-targeting molecular imprinted polymer (MT-MIP) and combined with UV spectrophotometric approaches provide advantages in the examination of counterfeit samples. The current work describes an innovative and sustainable methodology for the simultaneous determination of tadalafil (TAD) and dapoxetine hydrochloride (DAP) in counterfeited honey and instant coffee aphrodisiac products utilizing a SPE exploiting MT-MIP. Besides, an innovative UV spectrophotometric method capable of resolving TAD in its pharmaceutical binary mixtures with DAP was developed. A novel computational approach was implemented to tailor the synthesis and design of the MT-MIP particles. Herein; we applied a newly developed UV spectrophotometric method which was based on Fourier self-deconvolution (FSD) method coupled with isoabsorptive point for determination of TAD and DAP in pharmaceutical dosage form. Besides we applied a SPE process based on the MT-MIP designed particles, assisting in the analysis of both drugs in counterfeited food samples. The SPE process and the UV spectroscopic methodology were assessed regarding their greenness using the pioneering GAPI, AGREEprep and AGREE greenness assessing tools. The synthesized MT-MIP particles were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The suggested spectrophotometric methods revealed a wider linear concentration range of 2-50 µg/mL with lower limits of detection in the range of 0.604 -0.994 µg/mL. Additionally, the suggested method demonstrated the utmost sensitivity and eco-friendliness for their target in its mixed dosage form and counterfeited food products. The SPE process and the developed analytical UV spectroscopic methodology were validated as per the ICH guidelines, and were found to be suitable for overseeing some counterfeiting activities in commercially available honey and instant coffee aphrodisiac products. An SPE based on MT-MIP magnetic-based polymer assisted with UV-spectroscopic method was successfully developed for analysis of tadalafil and dapoxetine hydrochloride in different matrices.

Speciation of Hexavalent Chromium in Aqueous Solutions Using a Magnetic Silica-Coated Amino-Modified Glycidyl Methacrylate Polymer Nanocomposite

A new magnetic amino-functionalized polymeric sorbent based on glycidyl methacrylate was synthesized and used in the separation of chromium Cr(VI) oxyanions sorption from aqueous solutions in a static batch system. The kinetic and isothermal parameters of the sorption process were determined. The experimental data were best fitted by a pseudo-second-order model with R2 = 0.994 and χ2 = 0.004. The sorption process of Cr(VI) removal by amino-functionalized sorbent was controlled by both intraparticle diffusion and liquid film diffusion. The equilibrium results showed that the sorption process is best described by the Freundlich model, followed closely by the Sips isotherm model, with a maximum sorption capacity of 64 mg/g. Quantum chemical modeling revealed that the sorption sites on the sorbent surface are fragments with diethylenetriamine and aminopropyl silane groups that coated the magnetic nanoparticles. The calculations showed that Cr(VI) oxyanions (Cr2O72-, CrO42- and HCrO4-) bind to both sorption sites, with diethylenetriamine centers slightly favored. The X-ray photoelectron spectroscopy (XPS) spectra demonstrate that the chromium bound to the sorbent in the form of Cr(III), indicating that the Cr(VI) can be converted on the surface of the sorbent to a less harmful form Cr(III) due to the sorbent's chemical composition.

In situ synthesis of the Fe3O4@poly(4-vinylpyridine)-block-polystyrene magnetic polymer nanocomposites via dispersion RAFT polymerization

This work presents a facile strategy for the generation of Fe3O4@poly(4-vinylpyridine)-block-polystyrene (Fe3O4@P4VP-b-PS) magnetic polymer nanocomposites. P4VP-b-PS nanoparticles prepared by dispersion RAFT polymerization of styrene in methanol/water in the presence of macro-P4VP chain transfer agent was employed as templates to grow Fe3O4 on polymeric network templates. With the following addition of FeCl3 into the above polymer colloids, pyridyl moieties in P4VP block of nanoparticles could further react with Fe3+ through a coordination reaction to generate Fe3+@P4VP-b-PS nanoparticles. After the subsequent addition of FeCl2 and NH3⋅H2O, the co-precipitation reaction occurred on the surface of the polymeric nanoparticle to form Fe3O4@P4VP-b-PS magnetic polymer nanocomposites. Herein, FT-IR, XRD, TGA, XPS, TEM and VSM were applied to characterize the morphology, structure and magnetism performance of the synthesized magnetic polymeric nanocomposites.

Recent Trends in Magnetic Polymer Nanocomposites for Aerospace Applications: A Review.

Polymers have had an enormous impact on science and technology, and their interest relating to the development of new macromolecular materials has exponentially increased. Polymer nanocomposites, materials based on a polymeric matrix covalently coupled to reinforcement, display properties of both components. In the aerospace industry, polymer nanocomposites are attractive due to their promising characteristics, among which lightness, mechanical and thermal resistance, radiation and corrosion resistance, and conductive and magnetic properties stand out. The use of them, instead of metal-based materials, has allowed the optimization of design processes and applications in order to provide safer, faster, and eventually cheaper transportation in the future. This comparative review collects the most relevant and prominent advances in the development of polymer nanocomposites with aerospace applications starting from basic aspects such as the definition of polymer nanocomposite to more specialized details such as synthesis, characterization, and applications, in addition to proposing new research branches related to this topic.

Magnetic poly(ε-caprolactone)-based nanocomposite membranes for bone cell engineering

Magnetic polymer nanocomposites manipulatable by an external magnetic field have a great potential for bone tissue regeneration. Various strategies have been proposed for their fabrication, as uniform distribution of magnetic nanoparticles (MNPs) within the polymer matrix remains to be the main challenge. The aim of this study was to design poly(ε-caprolactone) (PCL) matrix containing iron oxide nanoparticles stabilized by saturated fatty acids with the increasing number of carbon atoms, i.e., caprylic (CA), palmitic (PA), and stearic acids (SA). We investigated the effect of the type of fatty acid and the content of particles in nanocomposite membranes on their physicochemical properties and biological response toward the SAOS-2 cells. The incorporation of the MNPs in PCL matrix resulted in a gradual increase of Young’s modulus, a slight decrease of tensile strength, and a significant decrease of stress and strain at break. The addition of SA-stabilized MNPs (1 wt%) in the PCL matrix increased its strength. The membranes containing CA-stabilized MNPs remained non-toxic towards SAOS-2 cells, while the cytotoxicity of other nanocomposites increased with the enhanced length of carbon chains of fatty acids stabilizing MNPs, as well as with their increasing content in membranes.

Highly porous chitosan based magnetic polymeric nanocomposite (PNC) for the removal of radioactive, Cs(I) and Sr(II) ions from aqueous solution

In the present study highly porous magnetic polymeric schiff base nanocomposite was fabricated using chitosan and 2-hydroxy-5-formylbenzoic acid in the presence of NiFe2O4. The analytical analysis (FTIR, TGA, XRD, BET, SEM, TEM and XPS) results support the successfully fabrication of NiFe2O4, polymeric matrix (PNC) and magnetic polymer nanocomposite (NiFe2O4@PNC). The surface area of NiFe2O4, and NiFe2O4@PNC was found to be 78.12, and 254 m2/g for NiFe2O4, and NiFe2O4@ PNC respectively. The NiFe2O4@PNC used for the adsorption of radioactive metal ions, Cs(I) and Sr(II) and the adsorption capacity was found to 232.12 mg/g and 212.5 mg/g respectively. The interaction between the NiFe2O4@PNC and both the metal ions were determine using adsorption kinetics and adsorptions isotherms models, which support the pseudo-second order and Langmuir adsorption models take part. The regeneration results revealed that the NiFe2O4@PNC retain 94.1 and 92.0 % adsorption capacity after six cycles with Cs(I) and Sr(II). These results demonstrate that the fabricated NiFe2O4@PNC can be used as an advanced and efficient adsorbent for adsorbing toxic inorganic and organic pollutants from contaminated water.

Studying the electrical conductivity and mechanical properties of irradiated natural rubber latex/magnetite nanocomposite

Abstract Nanocomposites have received voluminous interest due to the combination of unique properties of organic and inorganic component in one material. In this class, magnetic polymer nanocomposites are of particular interest because of the combination of excellent magnetic properties, stability, and good biocompatibility. This paper reports the preparation and characterization of nanocomposites films based on natural rubber in latex state (NRL) loaded with different concentrations of semiconducting magnetite nanoparticles (Fe3O4) (MNPs) (5, 10, 15, 20, and 30%). NRL (100%) and NRL/Fe3O4 nanocomposites were prepared by solution casting technique then, exposed to various irradiation doses (50, 70, 100 kGy).The nanocomposite’s morphological, and physical properties were investigated through various spectroscopic techniques such as Fourier-transformed infrared, X-ray diffraction, scanning electron, and transmission electron microscopies. The mechanical properties, including the tensile strength and elongation at break percentage (E b %) of the nanocomposites were also studied and compared with the 100% NRL films. Based on the results obtained from the mechanical study, it is found that the NRL/20% Fe3O4 nanocomposite film exhibited the highest tensile strength at 100 kGy. On the other hand, based on the conductivity study, it is found that, NRL/Fe3O4 nanocomposite with 10% magnetite exhibit the highest conductivity as the content of magnetite plays an important and effective role based on the high and homogeneous dispersity.

Microwave absorption and magnetic properties of thin-film Fe3O4 @polypyrrole nanocomposites: The synthesis method effect

In this study, a thin film of magnetic polymer nanocomposite for microwave absorption was prepared using a core-shell structure in an epoxy resin medium. The co-precipitation technique was used to synthesize the Fe3O4 NPs; and core-shell Fe3O4 @polypyrrole nanocomposites were made by two different synthesis methods through chemical oxidative polymerization with and without hydrochloric acid (HCl) and then, they were filmed by mixing the resulting powder with epoxy resin to explore their microwave absorption properties. The Fe3O4, Fe3O4 @PPy-A, and Fe3O4 @PPy-B nanostructures were characterised using Fourier transform infrared (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and thermogravimetric analysis (TGA) techniques, and the results confirmed synthesis of nanomaterial's pure structure. The transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FESEM) techniques were used to determine morphology, magnetic properties of the nanocomposites were investigated by vibrating-sample magnetometer (VSM) at room temperature and electrical conductivity were calculated by four-point probe method. Finally, the microwave absorption properties of Fe3O4, Fe3O4 @PPy-A, and Fe3O4 @PPy-B nanocomposites were determined by epoxy resin serving as a host using a vector network analyser. According to the results of assessing microwave absorption, it was found that addition of HCl played a significant role. However, the maximum reflection loss of the Fe3O4 @PPy-A and Fe3O4 @PPy-B nanocomposites was equal to − 33.8 dB (˃99.9%) at 11.5 GHz and − 26.2 dB at 7.2 GHz, but demonstrating an effective bandwidth of 6.5 and 1 GHz, respectively. Compared to other previously reported studies, microwave properties of the core-shell Fe3O4 @PPy-A nanocomposite not only had better reflection loss performance but also it possessed wider effective absorption bandwidth < −20 dB for thinner thickness of 1.5 mm.

Efficient inductively heated shape memory polyurethane acrylate network with silane modified nanodiamond@Fe3O4 superparamagnetic nanohybrid

Multifunctional magnetic shape memory polymer (SMP) nanocomposites with high sensitivity was synthesized through inclusion of silane functionalized [email protected]3O4 (S-NDF) hybrid nanoparticle into polycaprolactone (PCL) based polyurethane acrylate (PUA) matrix followed by in situ crosslinking of the matrix. Highly biocompatible and superparamagnetic nanodiamond(ND)@Fe3O4 nanohybrids were synthesized through in situ co-precipitation method. The morphological analysis suggested that S-NDFs filled PUAs (2 to 9 wt% loadings) well interacted with both soft and hard domains of the matrix. The base polymer and the nanocomposites presented excellent shape fixity ratio (above 97%) and shape recovery ratio (above 99.5%) in hot water. Furthermore, PUA/S-NDF nanocomposites with nanohybrid loading of 9 wt% exhibited excellent shape recovery rate (above 96%) in a very small magnetic field (H = 0.76 kA.m−1) as well as faster magnetic responsiveness compared to Fe3O4 loaded nanocomposites. Moreover, PrestoBlue cell viability assay suggested biocompatibility of the base polymers and the nanocomposites.

Treatment of Oil from the Oil Industry Wastewater by the Production of a Hydrophobic Magnetic Polymer Nanocomposites

A novel, economic and environment-friendly composite material based on magnetic hollow magnetite (Fe3O4) nanoparticle coated with a polyvinyl pyrrolidone (PVP) was produced to treat the oil from the oil industry wastewaters. The oils were readily removed via hydrophobic PVP -magnetite nanocomposite. In this study the physicochemical properties of the produced PVP-magnetite nanocomposite were investigated with Fourier transform infrared spectrophotometer (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) analysis. The effects of increasing PVP -magnetite nanocomposite concentrations, the effects of separation time, effect of pH on the removal of oil were investigated. The removals of individual oil types with different carbon (C) ring numbers (from C 9 up to C 25) were investigated during oil removal. The reusing capacity of PVP-magnetite nanocomposite was investigated after 40 cycling for oil removal. The removal yields for all pollutants in the oil industry was investigated. FTIR analysis results showed that in the spectrum of PVP-coated magnetite nanocomposite the peak at 2500 1/cm can be attributed to the stretching vibration of C−N and C═O. XRD spectrum of the synthesized PVP– magnetite composite nanoparticle exhibited that the dominant phase of the composite nanoparticle is magnetite with a particle size of 16.8 nm. TGA analysis showed that about 69% weight loss was observed at 500°C and this is attributed to decomposition of PVP. Nonane (9 C rings) and undecane (11 C rings) have high removal yields like 99.99% while the oils with high carbon rings such as, 80% ducosene (22 C rings) and 72% pentacosane (25 C rings) exhibited low yields. The aforementined nanoparticle can be used 29 times to remove the oil with a yield of 99.99%. The maximum CODdis, COD, TSS and oil removal efficiencies were 99%, 99.5%, 99% and 99.90% respectively, via adsorption with 3 mg/l hydrophobic PVP-Fe3O4 / Polimer nanocomposite.

Core-Shell Structured Magnetic Carboxymethyl Cellulose-Based Hydrogel Nanosorbents for Effective Adsorption of Methylene Blue from Aqueous Solution.

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.

Plasticized magnetic starch-based Fe3O4 clay polymer nanocomposites for phosphate adsorption from aqueous solution

Plastics contribute a magnificent role to modern civilization, but the waste becomes a huge burden to ecology and remains intact for a thousand years. Hence, the recent movement is shifted to biodegradable plastic. In this study, an attempt was made to introduce an added value to the environment where the bio-plasticized materials were used for phosphate removal. A G-plasticized magnetic starch-based Fe3O4 clay polymer nanocomposite (PNC) was synthesized to remove phosphate from the aqueous solution. It was synthesized from activated carbon (AC), coated iron oxide nanoparticles (CIONP), nanoclay (NC), and glycerol (G) as a plasticizer. The synthesized adsorbents were characterized with UV-Vis, SEM, XRD, and FTIR. The PNC and constituent (CIONP) were tested for phosphate removal through batch adsorption experiments. The adsorption capacity increases with increasing the adsorbent dose and decreases with an increase in phosphate concentration. The synthesized PNC effectively raised the constituent optimum phosphate ion adsorption pH from acidic (pH = 3) to slightly acidic (pH = 6). At the optimal pH, the CIONP and PNC maximum phosphate adsorption capacity (MPAC) was 3.12 and 2.31 mg P/g, respectively. In addition, the phosphate removal efficiency of PNC (45-95% at pH 6) was comparable to CIONP (58-97% at pH 3) under an initial 2–100 mg P/L. The adsorbents adsorption kinetics and isotherm study best described by the pseudo-second-order and Freundlich model, in turn. The SEM images support the conclusion, in which the PNC shows a heterogenous porous surface. Therefore, the adsorption mechanisms were mainly described by multilayer and chemical adsorption, such as electrostatic and ion exchange. It can be concluded that there is a positive synergistic effect between the biopolymer (starch) and nanomaterials that form the PNC. This study results propose the multiple added values of modified bio-plasticized material (with adsorbent) for environmental (phosphate) remediation.

5-Fluorouracil loaded magnetic cellulose bionanocomposites for potential colorectal cancer treatment

Magnetic polymer nanocomposites are inherently multifunctional and harbor assorted physiochemical actions for applications thereof as novel drug nanocarriers. Herein, Fe3O4-nanoparticles were supported on rice straw cellulose for 5-fluorouracil carrier abbreviated as MC/5-FU for potential colorectal cancer treatments. Several analyses indicated the multifunctional properties of MC/5-FU bionanocomposites. Transmission and scanning electron microscopy study demonstrated that Fe3O4 nanofillers covered the cellulose matrix. The drug release from MC/5-FU was evaluated under various pH and temperature conditions, showing the maximum release at pH 7.4 and 44.2 °C. In in vitro anticancer assay, MC/5-FU exhibited enhanced selectivity and anticancer actions against 2D monolayer and 3D tumour spheroid models colorectal cancer cells. The anticancer effects of MC/5-FU with magnetic targeting and heat induction were also examined. This easily synthesized MC/5-FU indicated the potential in application as a low-cost drug formulation for colorectal cancer treatments.

Polystyrene magnetic nanocomposite blend: An effective, facile, and economical alternative in oil spill removal applications

Finding an efficient and economical method to remediate oil spills on water is a priority worldwide. In this article, we propose a solution to this problem using polystyrene magnetic nanocomposite blends composed of polystyrene chains grafted on the surface of silica coated on iron oxide nanoparticles and polystyrene. The hydrophobic and oleophilic magnetic polymer nanocomposite collected oil from the water surface quickly and efficiently. However, when the magnetic polymer nanocomposite was blended with polystyrene, the resulting material also absorbed oil efficiently from the water surface. The blending technique made it easier to prepare the absorbent and dramatically decreased its cost. These new absorbents absorbed oil up to 5 times their own weight in only 5 minutes. The excellent hydrophobicity, low density, and easy magnetic separation makes these new absorbents a promising alternative to recover oil from spilled in fresh and marine water.

Controlled shape memory effects of magnetic polymer nanocomposites by induction heating

Interest in stimuli-responsive materials has increased rapidly, leading to a multitude of innovative applications in biomedical design. This study seeks to induce controlled shape memory effects through induction heating of magnetic polymer nanocomposites while retaining thermal consistency within attached hydrogel composites for various biomedical applications. Three commonly used polymer matrices were embedded with varying concentrations of magnetite nanoparticles to determine minimum and maximum loading effects on induction heating response and optimal shape memory effects. Thermal and morphological characterizations were performed to determine transition temperatures, followed by induction heating tests by way of an induction coil at different magnetic field strengths to determine heating rates, activation times and activation rates of shape memory effects for each polymer nanocomposite composition. Simultaneously, mechanically tunable sodium alginate and cellulose nanocrystal hydrogel composites were fabricated and characterized to determine hydrational, mechanical and thermal buffering properties. Induction heating tests revealed that all substrates exhibited a heating response; however, shape memory effects were observed only in poly(vinyl acetate) and Nylon 11. Moreover, all hydrogels displayed promising thermal dissipation, &lt;1°C per 20 s of heating, preventing any potential thermal shock to biological components. These unique properties will allow for successful employment of these multi-composite scaffolds in a multitude of biological applications.

Development of Aspartame Functionalized Magnetic Polymer Nanocomposites for the Zinc (II) Removal from Aqueous Solution

Development of Aspartame Functionalized Magnetic Polymer Nanocomposites for the Zinc (II) Removal from Aqueous Solution

Synthesis of Fe3O4/SiO2/Polypyrrole magnetic nanocomposite polymer powder: Investigation of structural properties and ability to purify of edible sea salts

In this study, Fe3O4/SiO2/polypyrrole magnetic nanocomposite polymer powder was chemically synthesized. The structure of the prepared composite powders were studied using scanning electron microscopy, FTIR and XRD techniques. The results showed that the prepared composites have a nanometer structure. The FTIR results confirmed the electrostatic interactions between the composite components. XRD also showed the crystal structure of Fe3O4 and its composites. Optimal nanocomposite powder was used to purify the salt of Lake Urmia. Salt samples were treated with powder and the chemical properties of salt were investigated before and after treatment. Qualitative tests performed on salt included COD, BOD, organic compounds, heavy metals, nitrate and nitrite, and color characteristics. Finally, the efficiency of the nanoparticle powder in the lake salt treatment was calculated. The results showed that the composite powder reduced BOD and COD as well as the heavy metal salts of the lake. Also, the organic compounds in the salt decreased and the color factors such as the white index of the salt increased. Under optimal conditions, Fe3O4/SiO2/PPy composite showed the best performance at 37 min of purification time. In general, Fe3O4/SiO2/PPy composite can be easily used to purify sea salts and also reduce environmental pollutants.

Simple synthesis of novel magnetic silver polymer nanocomposites with a good separation capacity and intrinsic antibacterial activities with high performance.

Two new coordination polymers namely, [(AgCN)4LS]n (1) and [(AgCN)3LN]n (2), were successfully synthesized by the reaction of AgNO3 and cyanide as a co-anion with LS[1,1'-(hexane-1,4-diyl)bis(3-methylimidazoline-2-thione] and LN[1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazole)propane] ligands in order to use them for the preparation of magnetic nanocomposites with MnFe2O4 nanoparticles by an efficient and facile method. They were then well characterized via numerous techniques, including elemental analysis, FT-IR spectroscopy, TGA, PXRD, SEM, TEM, EDX, VSM, BET, ICP, and single-crystal X-ray diffraction. The considered polymers and their magnetic nanocomposites with nearly the same antibacterial activity demonstrated a highly inhibitive effect on the growth of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacteria. By considering the simple separation and recyclable characters of the magnetic nanocomposites, these materials are suitable to be used in biological applications.

Magnetic Solid Phase Extraction Based on Nanostructured Magnetic Porous Porphyrin Organic Polymer for Simultaneous Extraction and Preconcentration of Neonicotinoid Insecticides From Surface Water.

In this study, a magnetic porphyrin-based porous organic polymer (MP-POP) nanocomposite was successfully synthesized according previous studies and applied as an adsorbent for simultaneous extraction and preconcentration of four neonicotinoid insecticides from surface river water. The MP-POP was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS), N2-adsorption/desorption analysis, Fourier Transform infrared spectroscopy (FTIR). The neonicotinoid insecticides were quantified using high performance chromatography coupled with diode array detector (HPLC-DAD). The MP-POP shown to have a high surface area, highly porous structure and strong affinity toward the investigated analytes. The adsorption capacities were 99.0, 85.5, 90.0, and 79.4 mg g−1 for acetamiprid, clothiandin, thiacloprid and imidacloprid, respectively. The influential parameters affecting the magmatic μ-solid phase extraction (M-μ-SPE) procedure were investigated using fractional factorial design and surface response methodology (RSM). Under optimum conditions, the method exhibited relatively low limit of detection in the range of 1.3–3.2 ng L−1, limit of quantification in the range of 4.3–11 ng L−1 and wide linearity (up to 600 μg L−1). The intraday and interday precision, expressed as the relative standard deviation (RSD) were <5%. The percentage recoveries for the four target analytes ranged from 91 to 99.3% for the spiked river water samples. The method was applied for determination of neonicotinoids in river water samples and concentrations ranged from 0 to 190 ng L−1.