Magnetic Carbon Nanotubes Research Articles

Radar-Absorbent Polymer Composites Filled with Magnetic Iron Powder and Carbon Nanotubes

Radar-Absorbent Polymer Composites Filled with Magnetic Iron Powder and Carbon Nanotubes

Magnetic Solid-Phase Extraction Based on Magnetite-Multiwalled Carbon Nanotubes of Non-Steroidal Anti-Inflammatories from Water Followed by LC-ESI-MS/MS.

An analytical method based on liquid chromatography-electrospray ionization-tandem mass spectrometry detection (LC-ESI-MS/MS) has been developed for the determination of pharmaceutical compounds in water samples. Five non-steroidal anti-inflammatory drugs (NSAIDs) namely Naproxen, Ketoprofen, Piroxicam, Diflunisal and Celecoxib were investigated. Magnetic solid phase extraction (MSPE) was used for sample pre concentration of water samples and magnetic carbon nanotubes (Fe3O4-MWCNTs) were considered as solid phase extraction sorbent. Important parameters influencing the extraction efficiency such as nature and volume of eluent, sample pH and adsorbent mass were optimized. The developed MSPE method involved 75mg of Fe3O4-MWCNTs sorbent, 5mL of water sample at pH = 4 and 5mL of 10% ammonia in methanol in the elution step. Under the optimized extraction conditions, linearity, detection and quantification limits and reproducibility were evaluated. The proposed method was successfully applied to the analysis of NSAIDs in surface waters, and mean recoveries of all the NSAIDs were above 90% with relative standard deviations < 17%. The detection and quantification limits were comprised between 0.05-3.6ng.mL-1 and 0.2-11.9ng.mL-1, respectively.

Cd(II) removal from phenols-bearing wastewater using magnetic carbon nanotubes

This project studied Cd(II) uptake from phenols-bearing wastewater using magnetic carbon nanotubes (MCNT) as adsorbent. Initially, Cd(II) complexation with various phenols was confirmed by FT-IR spectroscopy. Factors affecting Cd removal are: solution pH; type of phenol [phenol (Ph), 2-chlorophenol (2-CP), 2-nitrophenol (2-NP), and 2,4-dinitrophenol (2,4-DNP)]; Mag:CNT mass ratio; Cd:phenolic compound molar ratio; and the effect of order of adding adsorption components (MCNT, Cd(II), phenolic compound) to the extraction medium. It was found that the presence of phenols in the extraction medium caused a 10–50% decrease in Cd(II) uptake. This was probably due to a competition between phenols/surface functional groups towards Cd(II); or phenols/Cd(II) to occupy the surface functional groups. 2,4-DNP was selected as a model phenolic compound. The optimum adsorption conditions [1:1 M ratio of (Cd(II):2,4-DNP) at pH 6 using MCNT(1:1) adsorbent] resulted in adsorption capacity of 17.9 mg Cd g−1. The best order of adding reagents was (Cd(II) + MCNT(1:1)) and then 2,4-DNP. The regeneration of the adsorbent was possible by using 0.5 M HNO3 where 90% of adsorption efficiency was reserved after three times of successive use. Upon presence of co-existing ions, 75% of the adsorption efficiency was maintained. The applicability of the proposed adsorption method on real water samples was evaluated.

NiII NPs entrapped within a matrix of l-glutamic acid cross-linked chitosan supported on magnetic carboxylic acid-functionalized multi-walled carbon nanotube: a new and efficient multi-task catalytic system for the green one-pot synthesis of diverse heterocyclic frameworks.

In the present study, a new l-glutamic acid cross-linked chitosan supported on magnetic carboxylic acid-functionalized multi-walled carbon nanotube (Fe3O4/f-MWCNT-CS-Glu) nanocomposite was prepared through a convenient one-pot multi-component sequential strategy. Then, nickelII nanoparticles (NiII NPs) were entrapped within a matrix of the mentioned nanocomposite. Afterward, the structure of the as-prepared Fe3O4/f-MWCNT-CS-Glu/NiII nanosystem was elucidated by various techniques, including FT-IR, PXRD, SEM, TEM, SEM-based EDX and elemental mapping, ICP-OES, TGA/DTA, and VSM. In the next part of this research, the catalytic applications of the mentioned nickelII-containing magnetic nanocomposite were assessed upon green one-pot synthesis of diverse heterocyclic frameworks, including bis-coumarins (3a–n), 2-aryl(or heteroaryl)-2,3-dihydroquinazolin-4(1H)-ones (5a–r), 9-aryl-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-diones (7a–n), and 2-amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles (9a–n). The good-to-excellent yields of the desired products, satisfactory reaction rates, use of water solvent or solvent-free reaction medium, acceptable turnover numbers (TONs) and turnover frequencies (TOFs), along with comfortable recoverability and satisfying reusability of the as-prepared nanocatalyst for at least eight successive runs, and also easy work-up and purification procedures are some of the advantages of the current synthetic protocols.

Cd(II) removal from amino acids-bearing wastewater: Critical evaluation and comparison of using magnetic carbon nanotubes vs. magnetite

In the present work, two magnetic adsorbents (magnetic carbon nanotunes “MCNT” and magnetite “Mag”) were tested for cadmium “Cd(II)” removal from water in the presence of various amino acids “AA” (aspartic acid, glutamic acid “Glu”, glycine and cysteine). MCNT was prepared by initially oxidizing carbon nanotubes (CNT) by three different methods: nitric acid method, ammonium persulphate method, Hummer's method. Magnetite was then deposited on the oxidized CNT to produce the corresponding magnetic carbon nanotube adsorbents: NA-MCNT, APS-MCNT, HUM-MCNT, respectively. Adsorption of Cd(II) on various MCNT was investigated in the presence/absence of AA where various factors were studied: pH, oxidation method of CNT, type of AA, magnetite-to-CNT ratio. It was found that the presence of AA significantly reduced the adsorption capacity of MCNT towards Cd(II) at all pHs (reduction occurred from 49.8 mg g−1 to 12.5 mg g−1). Contrary adsorption capacity of Cd(II) on bare magnetite “Mag” was noticeably enhanced in the presence of AA (for Glu, enhancement occurred from 6.9 to 22.3 mg g−1). Due to cheapness of Mag relative to CNT, it was recommended to use Mag rather than MCNT for Cd(II) removal from AA-bearing water. So that the optimum uptake method was proposed using Mag at pH 8 in the presence of Glu at concentration ratio (1:3 Cd(II): Glu). Mag was selective towards Cd(II) even in the presence of co-existing ions. The use of Mag for five cycles decreased adsorption efficiency to 80% which indicated that adsorption system was cost effective. Real water samples gave higher adsorption of Cd(II) in the presence of Glu than in distilled water. As a conclusion, it was recommended to use Mag rather than MCNT for Cd(II) removal in the presence of AA.

Rational Design of Well-Dispersed Co Supported Magnetic N-Doped Carbon Nanotube for High Catalytic Activity Toward Reduction of 4-Nitrophenol

Rational Design of Well-Dispersed Co Supported Magnetic N-Doped Carbon Nanotube for High Catalytic Activity Toward Reduction of 4-Nitrophenol

Application of Magnetic Carbon Nanotube Composite Nanospheres in Magnetic Solid-Phase Extraction of Trace Perfluorinated Compounds from Environmental Water Samples

Application of Magnetic Carbon Nanotube Composite Nanospheres in Magnetic Solid-Phase Extraction of Trace Perfluorinated Compounds from Environmental Water Samples

Application of Magnetic Carbon Nanotube Composite Nanospheres in Magnetic Solid-Phase Extraction of Trace Perfluorinated Compounds from Environmental Water Samples

Application of Magnetic Carbon Nanotube Composite Nanospheres in Magnetic Solid-Phase Extraction of Trace Perfluorinated Compounds from Environmental Water Samples

Co-Enzymes based nanoflowers incorporated-magnetic carbon nanotubes: A new generation nanocatalyst for superior removal of cationic and anionic dyes with great repeated use

Synthetic dyes leading to substantial discharge in various industrial areas such as textile, plastics, food, and cosmetics, have growingly threatened all livings. Although enzymes have been used for dye degradation, weak stability against changes in reaction environment, lack of reusability and high cost have strictly limited their use. Herein, we have developed co-enzymes nanoflowers incorporated-magnetic carbon nanotube nanocomposite as a novel and efficient nanocatalyst for superior degradation of malachite green (MG) and acid orange 7 (AO7) as model cationic and anionic dyes with excellent cyclic use. The HRP-Lac NF@mCNT nanocomposite (NC) containing horseradish peroxidase–laccase nanoflower (HRP-Lac NF) and iron oxide nanoparticles (Fe 3 O 4 NPs) decorated magnetic carbon nanotube (mCNT) was systematically employed in dye degradation as functions of pH, reaction time, dye type and reusability. This HRP-Lac NF@mCNT nanocomposite acted as one malfunctional nanoplatform since both HRP and Lac enzymes were used for rapid and efficient dye removal, Fe 3 O 4 NPs provided cyclic use and omitting the centrifugation step, and CNT functioned as a unique platform for NFs and Fe 3 O 4 NPs deposition. We demonstrated that HRP-Lac NF@mCNT NC induced ∼ 90 % MG and ∼ 85% AO7 decolorization in 20 min at pH 7.4 while it almost completely decolorized MG and AO7 in 60 min. In addition, ∼ 95% MG and ∼ 85% AO7 decolorization were accomplished even after 16 cycling use of HRP-Lac NF@mCNT NC. We claim that HRP-Lac NF@mCNT NC induced dye decolorization with dual mechanisms, enzymatic degradation, and physical adsorption. • Preparation of horseradish peroxidase–laccase co-enzymes nanoflower incorporated-magnetic carbon nanotubes. • Rapid and efficient dye degradation against a cationic and an anionic dye. • Magnetic property for repeated use.

Removal of antimonite (Sb(III)) from aqueous solution using a magnetic iron-modified carbon nanotubes (CNTs) composite: Experimental observations and governing mechanisms

In this study, a novel nanoscale iron oxide (FeOx) modified carbon nanotubes composite (FeOx@CNTs) was synthesized through a combined ball milling–hydrothermal two-step method and tested for aqueous Sb(III) removal efficiency and mechanisms. FeOx nanoparticles was successfully loaded on the surface of CNTs through functional groups such as hydroxyl (–OH), C–H, and C–O to enhance the removal efficiency of Sb(III) through adsorption and surface complexation. At a dosage of 0.02 g, a FeCl3·6H2O-to-CNTs mass ratio of 3:1, and an initial solution pH of 6.3, the amount of Sb(III) removed by the prepared FeOx@CNTs reached 172 mg/g, which was 42.9 times higher than that of the pristine CNTs (4.01 mg/g). Chemical adsorption and oxidation were the main removal mechanisms. At the equilibrium Sb(III) concentration of 6.08 mg/L, 6.56% of initial Sb(III) was adsorbed onto the surface of FeOx@CNTs, and 81.3% of initial Sb(III) was oxidized to Sb(V) with lower toxicity. The pseudo-second-order kinetic model could better describe the adsorption of Sb(III) onto the FeOx@CNTs composite, indicating that adsorption was mainly controlled by chemical sorption. In the adsorption isotherm equation, the Redlich–Peterson model provided a better fit of Sb(III) adsorption onto the FeOx@CNTs composite than the Langmuir and Freundlich models, which further indicated that the adsorption process was a hybrid removal process dominated by chemical sorption. The presence of CO32− slightly promoted the removal of Sb(III) from aqueous solution. The synthesized composite was magnetic and could be easily separated from the solution by an external magnetic field at the end of the sorption experiment. Based on these findings, the FeOx@CNTs nanocomposite is expected to provide an environmentally-friendly adsorbent with a strong sorption capacity for remediating Sb(III) in water environments.

Determination of morphine, codeine, and thebaine concentrations from poppy seed tea using magnetic carbon nanotubes facilitated dispersive micro-solid phase extraction and GC-MS analysis

With tightening enforcement and restrictions amid the opioid epidemic, poppy seed tea is consumed as an alternative to mitigate the withdrawal symptoms or as a home remedy to relieve pain and stress. Previously published studies suggested the potential danger of consuming tea brewed with a moderate to a large amount of poppy seed. In this study, the effects of small quantity and repeat brewing on opiate concentrations were evaluated. A dispersive-micro solid phase extraction facilitated by magnetic carbon nanotubes (Mag-CNTs/d-µSPE) was developed, optimized, successfully validated, and applied to ten poppy seed tea samples using gas chromatography-mass spectrometry (GC-MS) analysis. A total of ten poppy seed samples were evaluated in this work. Two grams of bulk poppy seeds were brewed with 6 mL of heated and acidified DI water three times. The brewed tea samples were subjected to the validated Mag-CNTs/d-µSPE/GC-MS analysis. The total mean opiate concentrations obtained from three brews were 1.1–1926, 20.2–311, and 9.0–100 mg/kg for morphine, codeine, and thebaine, respectively. The total opiate yields obtained from the small quantity brewing, i.e., 6 g seed in 18 mL tea, in this study may provide minimal analgesic and euphoric effects. Over 80% of the total opiate yield was extracted in the first brew with acidified deionized water from the 10 min brewing period, and opiate yields from the second and third brew were minimal. However, potential overdose could occur for some tea samples when scaled up to the starter quantity of seed suggested for new users.

One-pot synthesis of β-cyclodextrin magnetic carbon nanotube (β-CD@MMWCNT) for effective removal of phenol from oily wastewater

In this work, a novel composite material based on β-cyclodextrin magnetic carbon nanotube (β-CD@MMWCNT) was developed by a one-pot method (in situ co-precipitation) and applied as an adsorbent to remove phenol from oily wastewater. The basic structure, surface morphology, as well as physical and chemical properties of the composite material were analyzed. β-CD@MMWCNT was successfully prepared, confirmed by the attachment of Fe3O4 and β-cyclodextrin particles on the surface. The adsorption behavior of phenol on β-CD@MMWCNT conformed to the Langmuir isotherm model and the pseudo-first-order kinetic model. The adsorption was a spontaneous endothermic process, and the adsorption capacity calculated by Langmuir model was 67.67 mg/g at 20 °C. Moreover, the adsorbent still maintained 85% of the adsorption capacity after 7 cycles. Specially, the adsorbent was used to adsorb phenol from simulated oily wastewater, and the removal rate of phenol reached 92.6%. And the possible adsorption mechanisms were also proposed by infrared and Raman spectroscopy. In summary, β-CD@MMWCNT can be used as a potential adsorbent to remove phenol from oily wastewater.

Performance comparison between solid phase extraction and magnetic carbon nanotubes facilitated dispersive-micro solid phase extractions (Mag-CNTs/d-\xb5SPE) of a cyanide metabolite in biological samples using GC\u2013MS

Dispersive-micro solid phase extraction (d-µSPE) has gained increasing attention due to its convenience, effectiveness, and flexibility for sorbent selection. Among a various selection of materials, magnetic carbon nanotubes (Mag-CNTs) is a promising d-µSPE sorbent with excellent separation efficiency in addition to its high surface area and adsorption capability. In this work, two different surface-modified Mag-CNTs, Mag-CNTs-COOH and Mag-CNTs-SO3H, were developed to facilitate d-µSPE (Mag-CNTs/d-µSPE). The cyanide metabolite, 2-aminothiazoline-4-carboxylic acid (ATCA), was selected to evaluate their extraction performance using gas chromatography–mass spectrometry (GC–MS) analysis. The Mag-CNTs-COOH enabled a one-step derivatization/desorption approach in the workflow; therefore, a better overall performance was achieved. Compared to the Mag-CNTs-SO3H/d-µSPE and SPE workflow, the one-step desorption/derivatization approach improved the overall extraction efficiency and reduced solvent consumption and waste production. Both Mag-CNTs/d-µSPE workflows were validated according to ANSI/ASB 036 guidelines and showed excellent analytical performances. The limit of detection (LOD) and limit of quantitation (LOQ) of ATCA in synthetic urine were 5 and 10 ng/mL, respectively, and that in bovine blood were achieved at 10 and 60 ng/mL. The SPE method’s LOD and LOQ were also determined at 1 and 25 ng/mL in bovine blood samples. The Mag-CNTs/d-µSPE methods demonstrated great potential to extract polar and ionic metabolites from biological matrices. The extraction processes of ATCA described in this work can provide an easier-to-adopt procedure for potential routine forensic testing of the stable biomarker in cyanide poisoning cases, particularly for those cases where the cyanide detection window has passed.

Flammulina velutipes-like Co@NCNTs enhancing the electromagnetic wave absorption performance

Magnetic nitrogen-doped carbon nanotubes have been recognized as promising microstructures for electromagnetic wave absorption, benefiting from the internal hollow structure, excellent electrical conductivity and easy functionalization. Herein, a new composite composed of the thin-wall carbon nanotubes coated with the cobalt nanoparticles (hereafter labelled as: Co@NCNTs) on the tip was designed and synthesized through high temperature pyrolysis process. Revealed by scanning electron microscopy and X-ray photoelectron spectroscopy, the geometric and electronic structures of product were susceptible to the carbonization temperature. With the multiple dielectric polarization relaxations, higher magnetism and good impedance matching, the flammulina velutipes-like Co@NCNTs-700 exhibited the strongest dielectric loss, magnetic loss and electromagnetic wave absorption performance. The minimum reflection loss value and effective absorption bandwidth was determined to be −21.0 dB at 4.96 GHz and 5.28 GHz, respectively, superior to the previous reports. Furthermore, the thickness is at 2 mm and the filler mass loading is only 10%. Therefore, our present Co@NCNTs materials will be an ultralight material as potential high-efficiency EMW absorber.

The selective adsorption performance and mechanism of multiwall magnetic carbon nanotubes for heavy metals in wastewater

The safe treatment of heavy metals in wastewater is directly related to human health and social development. In this paper, a new type of recyclable adsorbent is synthesized through the oxidation of enhancer and modification with magnetic nanoparticles. The new adsorbent not only inherits the advantages of multiwall carbon nanotubes (6O-MWCNTs), but also exhibits a new magnetic property and further improved adsorption capacity, which is conducive to the magnetic separation and recovery of heavy metals. The adsorption results indicate that multiwall magnetic carbon nanotubes (6O-MWCNTs@Fe3O4) have a good performance for Pb(II) selective adsorption, with a maximum adsorption capacity of 215.05 mg/g, much higher than the existing adsorption capacity of the same type of adsorbents. Under the action of an external magnetic field, 6O-MWCNTs@Fe3O4 that adsorbed metal ions can quickly achieve good separation from the solution. The joint characterization results of FTIR and XPS show that under the action of both coordination and electrostatic attraction, the C=O bond in the –COOH group is induced to open by the metal ions and transforms into an ionic bond, and the metal ions are stably adsorbed on the surface of 6O-MWCNTs@Fe3O4. Pb(II) has a stronger attraction than Cu(II) and Cd(II) to the lone pair of electrons in oxygen atoms to form complexes, due to the covalent index of Pb (6.41) is more larger than that of Cu (2.98) and Cd (2.71).These data provide a new type of recyclable adsorbent for the efficient treatment of heavy metal ions in wastewater and enrich relevant theoretical knowledge.

Enhanced flexible polypropylene fabric with silver/magnetic carbon nanotubes coatings for electromagnetic interference shielding

Flexible and excellent electromagnetic interference (EMI) shielding materials have attracted increasing attention due to the rapid development of intelligent flexible electronic. Herein, the lightweight, flexible, conductive and efficient EMI shielding silver (Ag)/ magnetic carbon nanotubes (mCNTs) composite coatings were decorated on polypropylene (PP) fabrics via a facile spray deposition technique. The mCNTs were fabricated with hydrogen bonding between Fe3O4 and functionalized CNTs. The conductivity and EMI shielding properties of the Ag/mCNTs composite coatings were significantly enhanced by the introduction of mCNTs. In the frequency of 8.2–12.4 GHz, the Ag/mCNTs composite coatings possessed superior EMI shielding effectiveness (SE) of 61.1 dB and specific SE (SSE/t) of 2811.78 dB cm2/g, which also displayed great stability, maintaining 91.6%, 80.2% and 69.8% of EMI SE after washing, abrasion and bending tests. Therefore, the Ag/mCNTs coated PP fabrics can be a reliable candidate to explore high-performance EMI shielding flexible electronic.

Magnetic carbon nanotubes-molecularly imprinted polymer coupled with HPLC for selective enrichment and determination of ferulic acid in traditional Chinese medicine and biological samples

A molecularly imprinted polymer (MIP) with magnetic carbon nanotubes (MCNTs) as carrier was synthesized and used for the enrichment and determination of ferulic acid (FA) by high-performance liquid chromatography (HPLC). The morphology and structure of the FA magnetic carbon nanotubes-molecularly imprinted polymers (MCNTs@FA-MIPs) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results demonstrated that the prepared MCNTs@FA-MIPs had excellent magnetic properties and uniform appearance. The adsorption properties of the novel MIP were studied by kinetic, and isothermal adsorption experiments. The results showed that the MCNTs@FA-MIPs exhibited relatively good uptake kinetics (equilibrium time, 2 h), high adsorption capacity (50 mg⋅g−1), fast separation, and good selectivity for the template molecule with a separation factor α of 1.73. The MCNTs@FA-MIPs combined with HPLC were successfully applied to the separation, enrichment, and determination of FA in a Ligusticum chuanxiong extract and in plasma of rats which had been administered with Taitai beauty essence. The recoveries for FA were 95.53–100.03 % with relative standard deviations (RSDs) less than 5.5%. The results confirmed that the proposed MCNTs@FA-MIPs offered efficient extraction of FA from traditional Chinese medicinal preparations and blood samples and with high specificity.

Investigation the Effect of Encapsulated Bromelain Enzyme in Magnetic Carbon Nanotubes on Colorectal Cancer Cells

Background: Bromelain (BL) is an enzyme extracted from Ananas comosus, which has been known for its therapeutic properties. Objectives: The anticarcinogenic activity of BL was examined with and without the presence of magnetic carbon nanotubes (MCNTs) against HT-29 colorectal cancer cells. Methods: The operational factors affecting BL adsorption, such as contact time (30, 60, 90, 120, and 180 min), adsorbent dosage (1 g/L and 5 g/L), initial bromelain concentration (50, 150, and 300 mg/L), and temperature (35 and 50°C) were studied in details. Then, cancer cells were exposed to various BL concentrations (0.1, 1, 10, and 100 μg/mL), and the cell viability was determined by methylthiazol tetrazolium (MTT) assay after 24, 48, and 72 h. Results: The highest adsorption of BL on nanotubes was at 41.62 mg/L and achieved at 35°C and 90 min at the initial concentration of 50 mg/L and 1 g/L of MCNTs. The adsorption followed the Freundlich model and second-order kinetics. The results indicated that MCNTs could be a potential effective adsorbent for the removal of BL. Conclusions: MTT assay indicated that BL at a concentration of 100 μg/mL alone and in combination with MCNTs efficiently inhibited the HT-29 cancerous cells. However, encapsulated BL had a considerable advantage of slow delivery, which is favorable for cancer treatment.

Synthesis of chitosan functionalized magnetic carbon nanotubes for dispersive solid‐phase extraction of bromocresol green

Abstract This study presents a new and rapid method for preconcentration, measurement, and removal of trace amounts of coloured wastewater using chitosan functionalized magnetic carbon nanotubes in aqueous samples. This method involves a two-phase system in which the donor phase contains an aqueous phase with bromocresol green, and the acceptor phase contains functionalized magnetic carbon nanotubes with chitosan. Experiments were carried out in two stages of extraction of bromocresol green from aqueous solution and desorption of bromocresol green using ethanol solvent. The samples were analysed by UV–Vis spectrophotometer. Extraction parameters were investigated such as the effect of organic solvent, pH of the donor and acceptor phases, extraction time, interference species, and volume of elution solvent. The isotherm of bromocresol green adsorption was fine described by the Langmuir model, and the adsorption capacity in the maximum was 28.49 mg g−1. The preconcentration factor and limit of detection for bromocresol green were 14.3 and 7.5 μg L−1, respectively. A linear range is observed between 0.1 and 20 mg L−1. Finally, the chitosan functionalized magnetic carbon nanotubes (Fe3O4@MWCNT-CN) exhibited a high potential for removing the bromocresol green from aqueous samples.

Hydrolytic enzyme modified magnetic nanoparticles: An innovative and green microextraction system for inorganic species in food samples

In the presented study, the usability of hydrolytic enzyme immobilized magnetic nanoparticles as an extraction agent for the microextraction of metal ions from food samples was investigated. α-amylase modified magnetic carbon nanotubes (α-amylase-Fe3O4/MWCNTs) was used as an extraction agent for direct microextraction of trace arsenic from food sample phase into liquid phase medium prior to its ICP-MS determination. In extraction studies using hydrolytic enzymes, it is impossible to recover the free soluble enzyme after extraction without losing its activity. In our study, this problem was overcome by immobilizing the hydrolytic enzyme on magnetic support. In this way, α-amylase-Fe3O4/MWCNTs as an extraction agent with a reuse property of at least six times was used. α-amylase-Fe3O4/MWCNTs was characterized by FT-IR, XRD, SEM, SEM-EDX, VSM, TGA, and DTG techniques. Optimization of the presented method was performed using 1568 A rice flour certified reference material. Analytical parameters such as type of hydrolytic enzyme, pH and volume of the aqueous phase, extraction temperature and ultrasonic irridation time were optimized. The microextraction step was performed in ultrasonic water bath within only ∼15 min. Limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD %) values for the developed method were found to be 14.3 μg kg−1, 47.3 μg kg−1 and 7.5%, respectively. The method was successfully applied to the analysis of arsenic contents of different rice and flour samples.