Thiol modified Fe3O4@SiO2 as a robust, high effective, and recycling magnetic sorbent for mercury removal

AbstractThe SiO2 shell was coated on Fe3O4 nanoparticle by hydrolyzation of Na2SiO3, and then thiol groups were modified on the Fe3O4@SiO2 through silanization reaction to form Fe3O4@SiO2–SH sorbents. Characterization with transmission electron microscope (TEM), Energy-dispersive spectroscope (EDS), and X-ray photoelectron spectroscopy (XPS) proved that SiO2 and thiol groups were successfully covered on the surface of Fe3O4 nanoparticle. The Fe3O4 core possessed superparamagnetism for magnetic separation, and the SiO2 shell could protect the Fe3O4 core from being oxidized or dissolved under acid solution and provide good modificability. Due to the strong interaction between mercury and thiol groups, the synthesized sorbents exhibited high adsorption capacity and good anti-interference ability during mercury adsorption. The maximum adsorption capacity calculated from Langmuir fitting was 148.8mg/g at pH 6.5, and the sorbents still maintained good adsorption ability at low solution pH and high concentration of coexisting cations. Mercury loaded on the sorbents could be easily desorbed with 1mol/L HCl containing 3wt.% of thiourea, and the sorbents showed good reusability. The adsorption capacities were still kept over 110mg/g in tested natural water samples, showing practical significance in remediation of mercury contaminated actual water

Dual cloud point extraction coupled with hydrodynamic-electrokinetic two-step injection followed by micellar electrokinetic chromatography for simultaneous determination of trace phenolic estrogens in water samples

A dual cloud point extraction (dCPE) off-line enrichment procedure coupled with a hydrodynamic-electrokinetic two-step injection online enrichment technique was successfully developed for simultaneous preconcentration of trace phenolic estrogens (hexestrol, dienestrol, and diethylstilbestrol) in water samples followed by micellar electrokinetic chromatography (MEKC) analysis. Several parameters affecting the extraction and online injection conditions were optimized. Under optimal dCPE-two-step injection-MEKC conditions, detection limits of 7.9-8.9 ng/mL and good linearity in the range from 0.05 to 5 mu g/mL with correlation coefficients R (2) a parts per thousand yenaEuro parts per thousand 0.9990 were achieved. Satisfactory recoveries ranging from 83 to 108 % were obtained with lake and tap water spiked at 0.1 and 0.5 mu g/mL, respectively, with relative standard deviations (n = 6) of 1.3-3.1 %. This method was demonstrated to be convenient, rapid, cost-effective, and environmentally benign, and could be used as an alternative to existing methods for analyzing trace residues of phenolic estrogens in water samples.A dual cloud point extraction (dCPE) off-line enrichment procedure coupled with a hydrodynamic-electrokinetic two-step injection online enrichment technique was successfully developed for simultaneous preconcentration of trace phenolic estrogens (hexestrol, dienestrol, and diethylstilbestrol) in water samples followed by micellar electrokinetic chromatography (MEKC) analysis. Several parameters affecting the extraction and online injection conditions were optimized. Under optimal dCPE-two-step injection-MEKC conditions, detection limits of 7.9-8.9 ng/mL and good linearity in the range from 0.05 to 5 mu g/mL with correlation coefficients R (2) a parts per thousand yenaEuro parts per thousand 0.9990 were achieved. Satisfactory recoveries ranging from 83 to 108 % were obtained with lake and tap water spiked at 0.1 and 0.5 mu g/mL, respectively, with relative standard deviations (n = 6) of 1.3-3.1 %. This method was demonstrated to be convenient, rapid, cost-effective, and environmentally benign, and could be used as an alternative to existing methods for analyzing trace residues of phenolic estrogens in water samples

Feasibility Analysis and Clinical Applicability of a Modified Type V Resection Method for Malignant Bone Tumors of the Proximal Humerus

Objective: The purpose of this study was to explore the feasibility and clinical applicability of a modified type V resection method for malignant bone tumors of the proximal humerus. Methods: The relevant anatomic MRI data from 30 normal adult shoulder joints were measured to analyze the feasibility of the modified type V resection method for malignant bone tumors of the proximal humerus. Sixteen patients with malignant bone tumors of the proximal humerus were treated with modified radical resection between March 2012 and April 2017. Recurrence of tumor was evaluated after surgery, and shoulder function was assessed according to the Enneking skeletal muscle tumor function scoring system. Results: Radiographic results showed that the modified type V resection method was feasible, and within the allowable range of the maximum longitudinal diameter (<29.8 mm) and depth (<4 mm). Surgery was successfully completed in all 16 cases, and pathological examination suggested that the purposes for radical resection had been achieved. All patients were followed up over 3–49 months (mean, 15.6 months). One patient had local recurrence at 12 months after surgery, and we performed upper limb amputation. The remaining 15 patients had good prosthesis survival. At the final follow-up, shoulder joint function had recovered compared with preoperative levels, with a mean Enneking score of 25.8 points (range, 24–27 points). Conclusion: Modified type V resection may be feasible for treating tumors of the proximal humerus, maintaining good early shoulder function

Photonic and magnetic dual responsive molecularly imprinted polymers: preparation, recognition characteristics and properties as a novel sorbent for caffeine in complicated samples

We demonstrated the construction and characteristics of photonic and magnetic dual responsive molecularly imprinted polymers (DR-MIPs) prepared by combination of stimuli-responsive polymers and a molecular imprinting technique. The resultant DR-MIPs of Fe3O4@MIPs exhibited specific affinity for caffeine and photoisomerization induced reversible uptake and release of caffeine upon alternate UV and visible light irradiation. With irradiation at 365 nm, 62.5% of the receptor-bound caffeine was released from the DR-MIPs back into solution. Subsequent irradiation with visible light caused 93.6% of the released caffeine to be rebound by the DR-MIPs. The novel DR-MIPs were used as a sorbent for the enrichment of caffeine from real water and beverage samples. Recoveries ranging from 89.5-117.6% were achieved. The magnetic property of DR-MIPs provided fast and simple separation while the photonic responsive property offered simple template elution with the assistance of UV-Vis irradiation. The simple, rapid and reliable DR-MIPs based method proved potentially applicable for trace caffeine analysis in complicated samples.We demonstrated the construction and characteristics of photonic and magnetic dual responsive molecularly imprinted polymers (DR-MIPs) prepared by combination of stimuli-responsive polymers and a molecular imprinting technique. The resultant DR-MIPs of Fe3O4@MIPs exhibited specific affinity for caffeine and photoisomerization induced reversible uptake and release of caffeine upon alternate UV and visible light irradiation. With irradiation at 365 nm, 62.5% of the receptor-bound caffeine was released from the DR-MIPs back into solution. Subsequent irradiation with visible light caused 93.6% of the released caffeine to be rebound by the DR-MIPs. The novel DR-MIPs were used as a sorbent for the enrichment of caffeine from real water and beverage samples. Recoveries ranging from 89.5-117.6% were achieved. The magnetic property of DR-MIPs provided fast and simple separation while the photonic responsive property offered simple template elution with the assistance of UV-Vis irradiation. The simple, rapid and reliable DR-MIPs based method proved potentially applicable for trace caffeine analysis in complicated samples

Magnetic Property, Heat Capacity and Crystal Structure of Mononuclear Compounds Based on Substitute Tetrazole Ligand

Three mononuclear compounds formulated as {M[(2-1H-tetrazol-5-yl)pyridine]2(H2O)2} (M = FeII (1), CoII (2), CuII (3)) were reported and synthesized. Their space group is monoclinic, P21/c, revealed by single-crystal X-ray diffraction. Antiferromagnetic interactions exist in Compounds 1, 2 and 3, as evidenced by magnetic and low-temperature heat capacity measurements. In addition, their thermodynamic functions were determined by a relaxation calorimeter, indicating that Compound 1 exhibits a Schottky anomaly in low-temperature heat capacity. This work can provide an important fundamental basis for the research of the thermophysical properties of molecular-based magnetic materials