scholarly journals Smart Synthesis of Trimethyl Ethoxysilane (TMS) Functionalized Core–Shell Magnetic Nanosorbents Fe3O4@SiO2: Process Optimization and Application for Extraction of Pesticides

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4827 ◽  
Author(s):  
Khalid Al-Saad ◽  
Ahmed A. Issa ◽  
Sourour Idoudi ◽  
Basem Shomar ◽  
Mohammad A. Al-Ghouti ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Magnetic Particles ◽  
Solid Phase ◽  
Desirability Function ◽  
Magnetic Solid Phase Extraction ◽  
Magnetic Core ◽  
Significant Variable ◽  
Pareto Chart ◽  
Magnetite Fe3o4

In the current study, a smart approach for synthesizing trimethyl ethoxysilane–decorated magnetic-core silica-nanoparticles (TMS-mcSNPs) and its effectiveness as nanosorbents have been exploited. While the magnetite core was synthesized using the modified Mössbauer method, Stöber method was employed to coat the magnetic particles. The objective of this work is to maximize the magnetic properties and to minimize both particle size (PS) and particle size distribution (PSD). Using a full factorial design (2k-FFD), the influences of four factors on the coating process was assessed by optimizing the three responses (magnetic properties, PS, and PSD). These four factors were: (1) concentration of tetraethyl-orthosilicate (TEOS); (2) concentration of ammonia; (3) dose of magnetite (Fe3O4); and (4) addition mode. Magnetic properties were calculated as the attraction weight. Scanning electron microscopy (SEM) was used to determine PS, and standard deviation (±SD) was calculated to determine the PSD. Composite desirability function (D) was used to consolidate the multiple responses into a single performance characteristic. Pareto chart of standardized effects together with analysis of variance (ANOVA) at 95.0 confidence interval (CI) were used to determine statistically significant variable(s). Trimethyl ethoxysilane–functionalized mcSNPs were further applied as nanosorbents for magnetic solid phase extraction (TMS-MSPE) of organophosphorus and carbamate pesticides.

scholarly journals Magnetic Solid-Phase Extraction of Cadmium Ions by Hybrid Self-Assembled Multicore Type Nanobeads

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 229
Author(s):  
Gabriela Buema ◽  
Adrian Iulian Borhan ◽  
Daniel Dumitru Herea ◽  
George Stoian ◽  
Horia Chiriac ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Self Assembly ◽  
Carboxymethyl Cellulose ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Spatial Arrangement ◽  
Ion Concentration ◽  
Cadmium Removal ◽  
Ferromagnetic Nature ◽  
Pseudo Second Order

Novel hybrid inorganic CoFe2O4/carboxymethyl cellulose (CMC) polymeric framework nanobeads-type adsorbents with tailored magnetic properties were synthesized by a combination of coprecipitation and flash-cooling technology. Precise self-assembly engineering of their shape and composition combined with deep testing for cadmium removal from wastewater are investigated. The development of a single nanoscale object with controllable composition and spatial arrangement of CoFe2O4 (CF) nanoparticles in carboxymethyl cellulose (CMC) as polymeric matrix, is giving new boosts to treatments of wastewaters containing heavy metals. The magnetic nanobeads were characterized by means of scanning electron microscopy (SEM), powder X-ray diffraction analysis (XRD), thermogravimetric analysis (TG), and vibrational sample magnetometer (VSM). The magnetic properties of CF@CMC sample clearly exhibit ferromagnetic nature. Value of 40.6 emu/g of saturation magnetization would be exploited for magnetic separation from aqueous solution. In the adsorptions experiments the assessment of equilibrium and kinetic parameters were carried out by varying adsorbent dosage, contact time and cadmium ion concentration. The kinetic behavior of adsorption process was best described by pseudo-second-order model and the Langmuir isotherm was fitted best with maximum capacity uptake of 44.05 mg/g.

scholarly journals Colorimetric determination of trace orthophosphate in water by using C18-functionalized silica coated magnetite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanpaseuth Phouthavong ◽  
Supone Manakasettharn ◽  
Duangkamon Viboonratanasri ◽  
Siriwit Buajarern ◽  
Panida Prompinit ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Ammonium Bromide ◽  
Colorimetric Determination ◽  
Blue Solution ◽  
Cetyl Trimethyl Ammonium ◽  
Highly Sensitive Detection ◽  
Phosphomolybdenum Blue

AbstractIn this study, we customized magnetic sorbents by functionalizing silica coated magnetite with octadecyl(C18)silane (Fe3O4@SiO2@C18). This sorbent was intended for the determination of trace orthophosphate (o-PO43−) in unpolluted freshwater samples. The o-PO43− was transformed to phosphomolybdenum blue (PMB), a known polyoxometalate ion. Then the PMB were coupled with cetyl trimethyl ammonium bromide (CTAB), cationic surfactant, in order to hydrophobically bound with the Fe3O4@SiO2@C18 particles through dispersive magnetic solid-phase extraction (d-MSPE) as part of sample preconcentration. The PMB–CTAB–magnetic particles are simply separated from the aqueous solution by the external magnet. The acidified ethanol 0.5 mL was used as PMB-CTAB eluent to produce an intense blue solution, which the absorbance was measured using a UV–Vis spectrophotometer at 800 nm. The proposed method (employing 2 mg of Fe3O4@SiO2@C18) yielded an enhancement factor of 32 with a linear range of 1.0–30.0 µg P L−1. Precision at 6.0 µg P L−1 and 25.0 µg P L−1 were 3.70 and 2.49% (RSD, n = 6) respectively. The lower detection limit of 0.3 µg P L−1 and quantification limit of 1.0 µg P L−1 allowed trace levels analysis of o-PO43− in samples. The reliability and accuracy of the proposed method were confirmed by using a certified reference material. Our method offers highly sensitive detection of o-PO43− with simple procedures that can be operated at room temperature and short analysis time.

scholarly journals Magnetic Mesoporous Silica Composite for Enhanced Preconcentration of Selected Organophosphorus Pesticides in Fruits

2020 ◽  
Vol 20 (4) ◽  
pp. 729 ◽  
Author(s):  
Nur Husna Zainal Abidin ◽  
Wan Nazihah Wan Ibrahim ◽  
Nor Suhaila Mohamad Hanapi ◽  
Nor’ashikin Saim
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Magnetic Particles ◽  
Solid Phase ◽  
Organophosphorus Pesticides ◽  
Magnetic Solid Phase Extraction ◽  
High Concentration ◽  
Relative Standard ◽  
Fruit Samples ◽  
Mcm 41

In the present work, MCM-41 coated magnetic particles (Fe3O4-MCM-41) composite was synthesized and employed as an effective adsorbent in magnetic solid phase extraction (MSPE) of three selected organophosphorus pesticides (OPPs) namely chlorpyrifos, diazinon and parathion methyl from grape and strawberry samples prior to high performance liquid chromatography with UV detection (HPLC-UV). The synthesized sorbent was physicochemically and morphologically characterized via Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and N2 adsorption analysis. The main parameters on the extraction efficiency of selected OPPs, including extraction time, desorption solvent, desorption time, and sorbent dosage, were thoroughly optimized. Compared to MCM-41 sorbent, the newly synthesized Fe3O4-MCM-41 adsorbent shows a linear response (0.1-5.00 mg L–1) with good determination coefficients ranging from 0.9900 to 0.9980, low limits detection (LODs), 0.02-0.15 mg L–1 and low limit quantifications (LOQs), 0.06-0.40 mg L–1. The precision as relative standard deviation (%RSD) of the proposed MSPE method was studied at low and high concentration (0.1-5.0 mg L–1) based on intra-day (1.0 to 6.0%, n = 3) and inter-day (1.0 to 7.0%, n = 3), respectively. Fruit matrices were used to assess the field applicability of the sorbents. Comparatively, Fe3O4-MCM-41 achieved excellent percent recovery (85–120%) compared to the MCM-41 (70–110%). The result revealed that the Fe3O4-MCM-41 composite was efficient sorbent with good capability for the preconcentration of selected OPPs from fruit samples.

Sign in / Sign up

Export Citation Format

Share Document