Magnetic Separation Method Research Articles

Study on magnetic separation for decontamination of cesium contaminated soil by using superconducting magnet

The accident of Fukushima Daiichi nuclear power plant caused the diffusion of radioactive cesium over the wide area. We examined the possibility of applying magnetic separation method using the superconducting magnet, which can process a large amount of the soil in high speed, to the soil decontamination and volume reduction of the radioactive cesium contaminated soil. Clay minerals are classified as 2:1 and 1:1 types by the difference of their layer structures, and these types of minerals are respectively paramagnetic and diamagnetic including some exception. It is known that most of the radioactive cesium is strongly adsorbed on the clay, especially on 2:1 type clay minerals. It is expected that the method which can separate only 2:1 type clay minerals selectively from the mixture clay minerals can enormously contribute to the volume reduction of the contaminated soil. In this study, the components in the clay before and after separation were evaluated to estimate the magnetic separation efficiency by using X-ray diffraction. From the results, the decontamination efficiency and the volume reduction ratio were estimated in order to examine the appropriate separation conditions for the practical decontamination of the soil.

Isolation and Culture of Endothelial Cells from the Embryonic Forebrain

Embryonic brain endothelial cells can serve as an important tool in the study of angiogenesis and neurovascular development and interactions. The two vascular networks of the embryonic forebrain, pial and periventricular, are spatially distinctive and have different origins and growth patterns. Endothelial cells from the pial and periventricular vascular networks have unique gene expression profiles and functions. Here we present a step-by-step protocol for isolation, culture, and verification of pure populations of endothelial cells from the periventricular vascular network (PVECs) of the embryonic forebrain (telencephalon). In this approach, telencephalon devoid of pial membrane obtained from embryonic day 15 mice is minced, digested with collagenase/dispase, and dispersed mechanically into a single cell suspension. PVECs are purified from cell suspension using positive selection with anti-CD-31/PECAM-1 antibody conjugated to MicroBeads using a strong magnetic separation method. Purified cells are cultured on collagen 1 coated culture dishes in endothelial cell culture medium until they become confluent and further subcultured. PVECs obtained with this protocol exhibit cobblestone and spindle shaped phenotypes, as visualized by phase-contrast light microscopy and fluorescence microscopy. Purity of PVEC cultures was established with endothelial cell markers. In our hands, this method reliably and consistently yields pure populations of PVECs. This protocol will benefit studies aimed at gaining mechanistic insights into forebrain angiogenesis, understanding PVEC interactions, and cross-talks with neuronal cell types and holds tremendous potential for therapeutic angiogenesis.

CD133 antibody-conjugated immunoliposomes encapsulating gemcitabine for targeting glioblastoma stem cells.

CD133+ cells in glioblastoma multiforme (GBM) display glioma stem cell (GSC) properties and have been considered to be the culprit in tumor recurrence, justifying the exploration of potential therapeutic modalities targeting CD133+ cells. Such strategies require a drug-delivery vehicle, and increasingly, the unique properties of PEGylated liposomes are being exploited for this purpose. More advanced liposomal delivery studies have suggested conjugation of CD133 antibodies as a suitable method for targeting GSCs. For targeting studies, GSCs separated from U87 GBM cells using a magnetic bead separation method were challenged with liposomes encapsulating gemcitabine (GEM) conjugated with a CD133 monoclonal antibody (PEG-lipo-CD133-GEM). An in vitro study showed that conjugation of CD133 antibody significantly enhanced the cytotoxicity of GEM through endocytosis of CD133 surface markers overexpressed on GSCs. The anti-tumor effect of PEG-lipo-CD133-GEM was 15 times higher than that of free GEM, presumably reflecting the specific targeting of the CD133 surface marker by PEG-lipo-CD133-GEM and the enhanced stability and cytotoxicity through the PEGylated liposome formulation in xenograft models. Moreover, monitoring of body weight changes showed that the use of PEGylated liposomes significantly reduced the toxicity of GEM. Taken together, our studies demonstrate that PEG-lipo-CD133-GEM shows promise for the treatment of gliomas in vitro and in xenograft models.

Experimental Study on Magnetic Separation of Oolitic Hematite Ore

To enhance effective use of resources, we use magnetic separation method on the experiment study of a refractory oolitic hematite ore. Research showed that: the grade of raw ore (TFe) was 47.44%, and magnetic iron grade (MFe) was 28.59%. Through magnetic separation experiment, three-step magnetic separation process was chosen. The magnetic field intensity (MFI) of three magnetic separation processes was 1200Oe800Oe400Oe, respectively. After first magnetic separation, the preliminary concentrates was reground to fineness of 87% (-500 mesh). Under the optimal experiment conditions, an iron ore concentrate with grade of 61.11% and a good recovery of 44.35% was obtained.

The effect of chitosan-tripolyphosphate nanoparticles on maturation and function of dendritic cells

Nanoparticles can decrease the defects of usual drug and gene delivery systems. Chitosan is a low-toxicity, biodegradable, biocompatible, and safe polymer which is used in the production of nanoparticles. Nanoparticles including chitosan-tripolyphosphate (TPP) can affect the immune cells including dendritic cells (DCs) as the most potent antigen-presenting cells with a pivotal role in both humoral and cellular immunity. For efficient antigen presentation, DCs need to become mature and express high levels of class II major histocompatibility complex (MHC-II) as well as costimulatory molecules, including CD40 and CD86 molecules. In this study, we investigated the effects of chitosan-TPP nanoparticles on DC maturation and function. Chitosan-TPP was synthesized by ionotropic gelation methods from chitosan and TPP salt, and DCs were isolated from mouse spleen using the magnetic cell separation method. DCs were treated with chitosan-TPP nanoparticles during an overnight cell culture and phenotypic and functional characteristics of chitosan-TPP-treated DCs were evaluated by flow cytometric analysis. Our results showed that chitosan-TPP induced DC maturation. Moreover, chitosan-TPP-treated DCs were shown to be efficient inducers of T cell proliferation in allogenic mixed lymphocyte reaction. Indeed, chitosan-TPP as an adjuvant is able to induce DC maturation which is a vital step in efficient antigen presentation and activation of the immune system. Thus, chitosan-TPP nanoparticles can be used as a dual-function agent in clinical immunotherapy methods aiming at using them in drug and gene delivery as well as in potentiating immune responses.

The Vanadium Titanium Magnetite Tailings of Chengde Area Comprehensive Recycling Situation and Development Trend

Summarized the siutuation of the vanadium titanium magnetite tailings recycling in Chengde, TiO2 in ilmenite tailings grade almost more than 2%, caused by TiO2 resources waste, put forward by gravity separation, magnetic separation,and flotation combined process method for titanium iron ore tailings reelection, and put forward the technological process selection by reducing the grinding fineness, increasing number of handpick and scavenging, adopt combination process and increasing flotation process to increase the recovery rate of TiO2, reduce TiO2 grade in the tailings.

Sequential Injection Magneto Chromatography Determination of Non-Steroidal Anti-Inflammatory Drugs in Pharmaceutical Formulations

A magnetic separation method based on the use of magnetic silica as the stationary phase in sequential injection chromatography was used for simultaneous determination of nonsteroidal anti-inflammatory drugs (acetaminophen, naproxen, diclofenac, and ibuprofen) in tablets. The method is based on a thin layer paramagnetic stationary phase retained on the inner wall of a mini-column through the action of an external magnetic field. The influence of the variables involved was evaluated and the optimal conditions were found to be: a methyl-silica magnetic adsorbent was used as the stationary phase, the mobile phase was methanol-water (60:40, v/v), pH 2.5 adjusted with 98% phosphoric acid, a flow rate 0.60 ml min−1, and UV detection at 225 nm. Under these conditions, the linear range of the calibration curve ranged from 3–6 mg L−1 to 100 mg L−1 with limits of detection ranging between 1 to 2 mg L−1. The proposed method was validated by comparing the results obtained against those provided by high performance liquid chromatography; no significant differences were seen.

Magnetic Separation System for Recovery of Glass Polishing Agent

The polishing agent, mainly composed of cerium oxide (CeO2), is used for fine polishing of products such as liquid crystal panels. The impurities of iron oxide, silica, and alumina get mixed in the cerium oxide-based polishing waste water. In order to reuse the polishing agent, it is necessary to remove these impurities. In this study, the impurities were removed utilizing the difference of magnetic susceptibility in order to recover the polishing agent. In our previous study, we proposed a technique to recover cerium oxide in high purity. In the first stage, iron oxide was removed from the polishing waste water by high-gradient magnetic separation. In the second stage, silica and alumina were removed by magneto-Archimedes method utilizing the magnetic force in vertical direction. In this study, we proposed a magnetic separation method utilizing the magnetic force in horizontal direction, and examined the application possibility of the method for continuous processing in practical use.

Mineralogical and chemical composition of magnetic fly ash fraction

Magnetic fractions of coal fly ashes from three power plants were obtained by wet magnetic separation method. Quartz and mullite were the crystalline minerals dominating the nonmagnetic fractions. Magnetic fractions contained magnetite, hematite, and, to a lesser extent, quartz and mullite. Iron speciation by Mossbauer spectroscopy indicated the presence of Fe2+ and Fe3+ in aluminosilicate glass in magnetic fractions apart from magnetite and hematite. Chemical analyses revealed that magnetic fractions had about 2.5 times higher concentrations of Co and one to two times higher concentrations of Ni, Cu, Zn, Mo, and Cd. The dominant magnetic minerals were ferrimagnetic, and multi domain and stable single domain grains contributed mainly to the magnetic enhancement of fly ash samples.

Efficient harvesting of marine microalgae Nannochloropsis maritima using magnetic nanoparticles

An efficient magnetic separation technology using Fe(3)O(4) nanoparticles was developed for harvesting marine microalgae Nannochloropsis maritima from culture broth. Recovery capacity of these nanoparticles was affected by microalgal growth phase and reached the peak value when the microalgal growth reached its maximal biomass after 18 days. The recovery efficiency of microalgal cells from the culture medium reached more than 95% at the particle dosage of 120 mg/L within 4 min. Electrostatic attraction at acidic pH and cell aggregation under neutral and alkaline conditions was beneficial for harvesting the algal cells. Higher operation temperature resulted in higher adsorption capacity of these nanoparticles for microalgawl cells. Reuse of the culture medium obtained from magnetic separation gave similar biomass production in comparison with that from centrifugation separation after 5 recycles. Together with these results provide a great potential in high-efficient and economical harvesting of tiny marine microalgae using magnetic separation technology in practice.

Recovery of iron from waste slag of pyrite processing using reduction roasting magnetic separation method

A considerable amount of waste slag from the pyrite roasting process is produced every year. Recovery of iron from the waste slag is of great interest for maximum use of mineral resource, reduction of environment impact and improvement of economical benefits to the related companies. The objectives of the present work are focused on: compare various options for recovery of iron from the waste slag and select the most advantageous option for industrial trial which is roasting of the waste slag under reducing condition followed by magnetic separation; investigate the optimum conditions for maximum recovery of iron from the waste slag. The experimental results show that under the treatment condition in this work about 70% of the iron was recovered from the waste slag, where the iron content in the concentrate is 57%. After the further treatment with chlorinated segregation–magnetic separation, the iron content in the recovered slag can reach 83%. After the treatment, sulphur content in the concentrate was reduced significantly and gangue materials, such as SiO2, Al2O3 and TiO2, were reduced effectively. This paper is mainly focused on the results of reduction roasting–magnetic separation.À chaque année, on produit une quantité importante de déchets de scorie provenant du procédé de grillage de la pyrite. La récupération du fer des déchets de scorie est d’un grand intérêt pour l’utilisation maximale de la ressource minérale, pour la réduction de l’impact sur l’environnement et pour l’amélioration des bénéfices économiques des compagnies associées. Les objectifs de ce travail sont centrés sur: la comparaison des diverses options de récupération du fer à partir des déchets de scorie et la sélection de l’option la plus avantageuse pour un essai industriel incluant le grillage des déchets de scorie avec réduction, suivi par la séparation magnétique; l’examen des conditions optimales d’une récupération maximale du fer à partir des déchets de scorie. Les résultats expérimentaux montrent qu’avec les conditions du traitement au cours de ce travail, on a récupéré environ 70% du fer à partir des déchets de scorie, où la teneur en fer dans le concentré était de 57%. Après un traitement additionnel par ségrégation chlorée–séparation magnétique, la teneur en fer dans la scorie de recouvrement pouvait atteindre 83%. Après le traitement, la teneur en souffre dans le concentré était réduite significativement et les matériaux de la gangue, comme le SiO2, l’Al2O3 et le TiO2, étaient effectivement réduits. Cet article se concentre principalement sur les résultats du grillage réducteur et séparation magnétique.

Effect of pH, ionic strength, foreign ions and temperatures on the sorption of Eu(III) on attapulgite-iron oxide magnetic composites

In this paper, the attapulgite-iron oxide magnetic composites were synthesized by coprecipitation method and were characterized by SEM, XRD and FTIR in detail. The characterization results indicated that the iron oxide was successfully formed on the surface of attapulgite. The prepared attapulgite-iron oxide magnetic composites were applied as adsorbents to remove Eu(III) from aqueous solutions by using batch sorption experiments under different experimental conditions. The sorption properties of Eu(III) on bare attapulgite were also performed as comparison. The results indicated that the sorption of Eu(III) on attapulgite-iron oxide magnetic composites was strongly dependent on pH and temperature. The attapulgite-iron oxide magnetic composites can be separated from aqueous solutions using magnetic separation method in large scale. At low pH values, the sorption of Eu(III) was influenced by ionic strength and pH obviously, while the sorption of Eu(III) was not affected by ionic strength at high pH values. The sorption of Eu(III) was dominated by ion exchange or outer-sphere surface complexation at low pH values, and mainly by inner-sphere surface complexation at high pH values. The thermodynamic parameters (i.e., ∆G°, ∆S°, ∆H°) calculated from the temperature dependent sorption isotherms indicated that the sorption of Eu(III) on attapulgite-iron oxide magnetic composites was an endothermic and spontaneous process. Although the sorption capacities of Eu(III) on attapulgite-iron oxide magnetic composites were a little lower than those of Eu(III) on bare attapulgite, the magnetic separation in large scale is suitable for the application of the magnetic composites in the preconcentration of Eu(III) from large volumes of aqueous solutions in possible real applications.

Synthesis of Quinoxaline Derivatives at Room Temperature Using Magnetic Material Separated from Coal Fly Ash

An efficient synthesis of quinoxalines derivatives is described using magnetic material separated from coal fly ash. Coal fly ash is a waste material generated in huge amount by burning of coal for the generation of electricity in thermal power station. It contains <TEX>$SiO_2$</TEX>, <TEX>$Al_2O_3$</TEX> and magnetic material in significant amounts, from which magnetic material was separated by using magnetic separation method. These separated magnetic material further characterized by XPS, XRD, EDS, FTIR, SEM, TEM and BET techniques. The merits of present method are mild reaction conditions, and also excellent yields and short reaction times.

Research on Magnetic Separation Methods for the Extraction of Nucleic Acids

The magnetic separation system is an important part of the automatic testing equipment. There are two methods to magnetize, internal magnetic attracting and external magnetic attracting. We compare the difference of the realization methods and the magnetic field distribution of the two ways. Then we select appropriate method to magnetize.

Magnetic separation of carbon-encapsulated Fe nanoparticles from thermally-treated wood char

Wood char, a by-product from the fast-pyrolysis process of southern yellow pine wood for bio-oil production, was carbonized with Fe nanoparticles (FeNPs) as a catalyst to prepare carbon-encapsulated Fe nanoparticles. A magnetic separation method was tested to isolate carbon-encapsulated Fe nanoparticles from the carbonized char. X-ray diffraction pattern clearly shows that Fe-containing materials were completely separated from the carbonized wood char mixture using a magnet. The amorphous carbon in the material which adhered to the magnetic bar was significantly decreased in comparison with the non-adhered material. Carbon graphitic layers encapsulated FeNPs were observed in the adhered material through high-resolution transmission electron microscopy. In addition, many long and tangled-multi-layered graphitic carbon structures grew from the surface of carbon-encapsulated Fe nanoparticles.

Impact of brief exercise on peripheral blood NK cell gene and microRNA expression in young adults

Natural killers (NK) cells are unique innate immune cells that increase up to fivefold in the circulating blood with brief exercise and are known to play a key role in first-response defense against pathogens and cancer immunosurveillance. Whether exercise alters NK cell gene and microRNA (miRNA) expression is not known. Thirteen healthy men (20-29 yr old) performed ten 2-min bouts of cycle ergometer exercise at a constant work equivalent to an average of 77% of maximum O2 consumption interspersed with 1-min rest. Blood was drawn before and immediately after the exercise challenge. NK cells were isolated from peripheral blood mononuclear cells using a negative magnetic cell separation method. We used Affymetrix U133+2.0 arrays for gene expression and Agilent Human miRNA V2 Microarray for miRNAs. A stringent statistical approach (false discovery rate < 0.05) was used to determine that exercise significantly altered the expression of 986 genes and 23 miRNAs. Using in silico analysis, we found exercise-related gene pathways where there was a high likelihood of gene-miRNA interactions. These pathways were predominantly associated with cancer and cell communication, including p53 signaling pathway, melanoma, glioma, prostate cancer, adherens junction, and focal adhesion. These data support the hypothesis that exercise affects the gene and miRNA expression pattern in the population of NK cells in the circulation and suggest mechanisms through which physical activity could alter health through the innate immune system.

Research on Classified Magnetic Separation of Oolitic Hematite from Guizhou Province

Oolitic hematite is considered to be one of the most refractory ores in the world due to its ultra fine disseminated grain size and complex mineral composition. Various magnetic separation methods were conducted on the oolitic hematite ore samples from Guizhou Province. Because the TFe grades of each size fraction of the grinding products were different from each other, the beneficiation process of “classification – low intensity magnetic separation – high intensity magnetic separation” was finally adopted to guarantee the quality of iron concentrates. After the determined magnetic separation, the relatively good technical indexes are obtained. The TFe grade of iron concentrates is increased from 38.7% to 46.1%, and the iron recovery is 81.7%.

Phage receptor binding protein-based magnetic enrichment method as an aid for real time PCR detection of foodborne bacteria

We present a novel phage receptor binding protein-based magnetic separation and pre-enrichment method as an alternative to the immunomagnetic separation methods by replacing antibodies with bacteriophage receptor binding proteins (RBPs). We couple the proposed RBP-based magnetic separation with real time PCR for rapid, sensitive and specific detection of Campylobacter jejuni cells in artificially contaminated skim milk, milk with 2% fat and chicken broth. Recovery rates, assessed by real time PCR, were greater than 80% for the samples spiked with as low as 100 cfu mL(-1) of C. jejuni cells. The specificity of capture was confirmed using Salmonella Typhimurium as a negative control where no bacteria were captured on the RBP-derivatized magnetic beads. The combination of RBP-based magnetic separation and real time PCR improved PCR sensitivity and allowed the detection of C. jejuni cells in milk and chicken broth samples without a time consuming pre-enrichment step through culturing. The total sample preparation and analysis time in the proposed RBP-based enrichment method coupled with real time PCR was less than 3 h.

Magnetic separation method for oil spill cleanup

Magnetic separation method for oil spill cleanup

Effect of Temperature on Recovery of Iron from Waste Slag of Pyrite Processing

Recovery of iron from the waste slag is of great interest for maximum use of mineral resource, reduction of environment impact and improvement of economical benefits to the related companies. This paper is mainly focused on the effect of the temperature on recovery of iron from waste slag of pyrite processing using reduction-roasting magnetic separation method. The experimental results show that under the treatment condition in this work about 70% of the iron was recovered from the waste slag, where the iron content in the concentrate is 57%. After the further treatment with chlorinated segregation-magnetic separation, the iron content in the recovered slag can reach 83%