Determination of Organochlorine Pesticides in Green Leafy Vegetable Samples via Fe3O4 Magnetic Nanoparticles Modified QuEChERS Integrated to Dispersive Liquid-Liquid Microextraction Coupled with Gas Chromatography-Mass Spectrometry

A fast method based on Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) modified QuEChERS integrated to dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry was established for the determination of 8 organochlorine pesticides (OCPs) in green leafy vegetables. The factors involved in the purification by QuEChERS and concentration by DLLME were optimized. In the QuEChERS process, Fe3O4 MNPs were used as a new impurity adsorbent after the sample extraction procedure by acetonitrile, which achieved phase separation rapidly. Carbon black was used as an alternative to costly graphitized carbon black without affecting the recovery. In the process of DLLME, 1 mL of the extract obtained by QuEChERS was used as the dispersive solvent, 40 μL of chloroform was used as the extractive solvent, and 4 mL of water was added. Making them mix well, then the dispersed liquid-liquid microextraction concentration was subsequently carried out. The enrichment factors of 8 OCPs ranged from 22.8 to 36.6. The recoveries of the proposed method ranged from 78.6% to 107.7%, and the relative standard deviations were not more than 7.5%. The limits of detection and limits of quantification were 0.15–0.32 μg/kg and 0.45–0.96 μg/kg, respectively. The method has been successfully applied to the determination of OCPs in green leafy vegetable samples.

Electrodecoration and Characterization of Superparamagnetic Iron Oxide Nanoparticles with Bioactive Synergistic Nanocopper: Magnetic Hyperthermia-Induced Ionic Release for Anti-Biofilm Action

The urgency for the availability of new antibacterial/disinfectant agents has become a worldwide priority. At the same time, along with the extensive use of other metal nanoparticles (NPs), the investigation of magnetic NPs (MNPs) in antibacterial studies has turned out to be an increasingly attractive research field. In this context, we present the preparation and characterization of superparamagnetic iron oxide NPs, electrodecorated with antimicrobial copper NPs, able to modulate the release of bioactive species not only by the NP’s stabilizer, but also through the application of a suitable magnetic field. Antimicrobial synergistic CuNPs stabilized by benzalkonium chloride have been used in the current study. We demonstrate the successful preparation of Cu@Fe3O4 MNPs composites through morphological and spectroscopic results. Additionally, an extensive magnetic characterization is reported, along with hyperthermia-induced copper ionic release. On the basis of our results, we propose a new generation of antimicrobial magnetic nanomaterials, whose bioactivity can be also tuned by the application of a magnetic field.

Mo@GAA-Fe3O4 MNPs: a highly efficient and environmentally friendly heterogeneous magnetic nanocatalyst for the synthesis of polyhydroquinoline derivatives

Polyhydroquinolines were obtained from a sequential four-component reaction between dimedone or 1,3-cyclohexandione, ethyl acetoacetate, or methyl acetoacetate as a β-ketoester, aldehydes, and ammonium acetate, with Mo@GAA-Fe3O4 MNPs as a green nanocatalyst.

An asymmetric Salamo-based Zn complex supported on Fe3O4 MNPs: a novel heterogeneous nanocatalyst for the silyl protection and deprotection of alcohols under mild conditions

The synthesis and characterization of a novel nanomagnetic Zn complex are shown. The obtained Zn complex applied in the silyl protection and deprotection of alcohols under green conditions.

Zr@IL-Fe3O4 MNPs as an efficient and green heterogeneous magnetic nanocatalyst for the one-pot three-component synthesis of highly substituted pyran derivatives under solvent-free conditions

Synthesis of highly substituted pyran derivatives using Zr@IL-Fe3O4 MNPs.

Preparation and Characterization of Fe3O4 nanoparticles and its application in Produced Water Treatment and Oil Recovery

Recently, considerable amounts of oil were produced from petroleum industries and lead to serious environmental problems. In this study, Fe3O4 (MNPs) were prepared using combustion synthesis method at temperature range from 150 to 350ºC and then applied with different concentrations to the oil/water emulsion. The synthesized MNPs were characterized using various analytical techniques, and their demulsification efficiencies were then evaluated. Results showed that the application of these nanoparticles could significantly improve the efficiency of the demulsification process, Furthermore, the prepared MNPs were still effective after being recycled for 4 cycles and give oil removal about 90%.

Bio-Fe3O4 magnetic nanoparticles promoted green synthesis of thioxo-1,3- oxazole derivatives: Study of antimicrobial and antioxidant activity

Aims and Objective: In this work 1,3-oxazoles were generated using multicomponent reaction of α-bromo ketones, alkyl (aryl) isothiocyanates, sodium hydride and Fe3O4 MNPs in water at room temperature in good yields. The nanoparticles that is generated via biosynthesis method have potentially valuable in different purposes such as organic synthesis. Materials and Methods: To study antioxidant ability of some synthesized thioxo-1,3-oxazoles, diphenyl-picrylhydrazine (DPPH) radical trapping and power of ferric reduction testes are employed. Among studied thioxo-1,3-oxazoles, 4b have good power for radical trapping and reduction activity than to standard antioxidant such as BHT and TBHQ. In addition, the antimicrobial activity of some thioxo-1,3-oxazoles was studied employing the disk diffusion test on Gram-positive bacteria and Gram-negative bacteria. The results of disk diffusion test showed that compound 4a, 4b, 4d and 4f prevented the bacterial growth. Results: Without employing catalyst, these reactions have low yield and busy mixture. The synthesis of compound 4a as sample reaction have alike yield in the presence of ZnO-NPs and Fe3O4 MNPs (entry 20 and entry 30) but removal of catalyst from the mixture of reaction after completing of reaction is comfortable in present of Fe3O4 MNPs. Structures of 4a–4i are confirmed by IR, 1H NMR, 13C NMR mass spectra. Conclusion: The reaction of α-bromo ketones, isothiocyanate and sodium hydride in the presence of catalytic amount of Fe3O4 MNPs in water generate 1,3-oxazole derivatives in good yields. Some advantages of performing these reactions with present procedure are carrying out these reactions in water as green solvent and simple removal of catalyst.