We are presenting magnetic molecularly imprinted polymer nanoparticles (m-MIPs) for solid-phase extraction and sample clean-up of paracetamol. The m-MIPs were prepared from magnetite (Fe3O4) as the magnetic component, paracetamol as the template, methacrylic acid as a functional monomer, and 2-(methacrylamido) ethyl methacrylate as a cross-linker. The m-MIPs were then characterized by transmission electron microscopy, FT-IR spectroscopy, X-ray diffraction and vibrating sample magnetometry. The m-MIPs were applied to the extraction of paracetamol from human blood plasma samples. Following its elution from the column loaded with the m-MIPs with an acetonitrile-buffer (9:1) mixture, it was submitted to HPLC analysis. Paracetamol can be quantified by this method in the 1 μg L?1 to 300 μg L?1 concentration range. The limit of detection and limit of quantification in plasma samples are 0.17 and 0.4 μg L?1. The preconcentration factor of the m-MIPs is 40. The HPLC method shows good precision (4.5 % at 50 μg L?1 levels) and recoveries (between 83 and 91 %) from spiked plasma samples. Figure
We are presenting magnetic molecularly imprinted polymer nanoparticles (m-MIPs) for solid-phase extraction and sample clean-up of paracetamol. The m-MIPs were applied to the extraction of paracetamol from human blood plasma samples相似文献
We are presenting magnetic molecularly imprinted polymer nanoparticles (m-MIPs) for solid-phase extraction and sample clean-up of paracetamol. The m-MIPs were prepared from magnetite (Fe3O4) as the magnetic component, paracetamol as the template, methacrylic acid as a functional monomer, and 2-(methacrylamido) ethyl methacrylate as a cross-linker. The m-MIPs were then characterized by transmission electron microscopy, FT-IR spectroscopy, X-ray diffraction and vibrating sample magnetometry. The m-MIPs were applied to the extraction of paracetamol from human blood plasma samples. Following its elution from the column loaded with the m-MIPs with an acetonitrile-buffer (9:1) mixture, it was submitted to HPLC analysis. Paracetamol can be quantified by this method in the 1 μg L−1 to 300 μg L−1 concentration range. The limit of detection and limit of quantification in plasma samples are 0.17 and 0.4 μg L−1. The preconcentration factor of the m-MIPs is 40. The HPLC method shows good precision (4.5 % at 50 μg L−1 levels) and recoveries (between 83 and 91 %) from spiked plasma samples.
An optical chemical sensor based on 2-mercaptopyrimidine (2-MP) in plasticized poly(vinyl chloride) (PVC) membrane incorporating
(N,N-diethyl-5-(octadecanoylimino)-5H benzo[a]phenoxazine-9-amine (ETH 5294) and sodium tetraphenyl borate (NaTPB) for batch and
flow-through determination of mercury ion is described. The response of the sensor is based on selective complexation of Hg2+ with 2-MP in the membrane phase, resulting in an ion exchange process between H+ in the membrane and Hg2+ in the sample solution. The influences of several experimental parameters, such as membrane composition, pH, and type and
concentration of the regenerating reagent, were investigated. The sensor has a response range of 2.0 × 10−9 to 2.0 × 10−5 mol L−1 Hg2+ with a detection limit of 4.0 × 10−10 mol L−1 and a response time of ≤45 s at optimum pH of 6.5 with high measurement repeatability and sensor-to-sensor reproducibility.
It shows high selectivity for Hg2+ over several transition metal ions, including Ag+, Cd2+, Co2+, Cr3+, Cu2+, Fe3+, Mn2+, Ni2+, and common alkali and alkaline earth ions such as Na+, K+, Mg2+, Ca2+, and Pb2+. The sensor membrane can be easily regenerated with dilute acid solutions. The sensor has been used for the determination
of mercury ion concentration in water samples. 相似文献
Dissociative recombination (DR) of water cluster ions H(+)(H(2)O)(n) (n=4-6) with free electrons has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). For the first time, branching ratios have been determined for the dominating product channels and absolute DR cross sections have been measured in the energy range from 0.001 to 0.7 eV. Dissociative recombination is concluded to result in extensive fragmentation for all three cluster ions, and a maximum number of heavy oxygen-containing fragments is produced with a probability close to unity. The branching ratio results agree with earlier DR studies of smaller water cluster ions where the channel nH(2)O+H has been observed to dominate and where energy transfer to internal degrees of freedom has been concluded to be highly efficient. The absolute DR cross sections for H(+)(H(2)O)(n) (n=4-6) decrease monotonically with increasing energy with an energy dependence close to E(-1) in the lower part of the energy range and a faster falloff at higher energies, in agreement with the behavior of other studied heavy ions. The cross section data have been used to calculate DR rate coefficients in the temperature range of 10-2000 K. The results from storage ring experiments with water cluster ions are concluded to partly confirm the earlier results from afterglow experiments. The DR rate coefficients for H(+)(H(2)O)(n) (n=1-6) are in general somewhat lower than reported from afterglow experiments. The rate coefficient tends to increase with increasing cluster size, but not in the monotonic way that has been reported from afterglow experiments. The needs for further experimental studies and for theoretical models that can be used to predict the DR rate of polyatomic ions are discussed. 相似文献
A new type of dispersive liquid–liquid microextraction is used for the determination of doxepin, citalopram, and fluvoxamine in aqueous matrices. This method is based upon the tandem utilization of dispersive liquid–liquid microextraction, and by providing a high sample clean‐up, it efficiently improves the applicability of the method in complicated matrices. For this purpose, in the first step, the analytes contained in an aqueous sample solution (8.0 mL) were extracted into an organic solvent, and then these analytes were simply back‐extracted into an aqueous acceptor phase (50 μL). The overall extraction time was 7 min, and very simple tools were required for this aim. Optimization of the variables affecting the method such as the type and volume of the organic solvent used and effect of ionic strength was carried out to achieve the best extraction efficiency. Under the optimized experimental conditions, tandem dispersive liquid–liquid microextraction with high‐performance liquid chromatography and UV detection showed a good linearity in the range of 10–5000 ng/mL. The limits of detection were in the range of 3–10 ng/mL. The Intra‐day precisions (relative standard deviation) were 9.2, 4.5, and 4.8, and the recoveries were 58.5, 52.9, and 39.3% for citalopram, doxepin, and fluvoxamine, respectively. 相似文献
A novel nanomagnetic composite heteropolyacid immobilized chitosan/Fe3O4 was prepared via a facile one-pot synthetic approach. This magnetically recoverable nanocatalyst, H3PMo12O40/chitosan/Fe3O4 (PMo/chit/Fe3O4), was fully characterized by XRD, FTIR, SEM and EDX analysis methods. A rapid, efficient and the chemoselective synthesis of different pyrano-pyrazole derivatives was achieved in excellent yields via a one-pot four-component reaction in the presence of catalytic amount of PMo/Chit/Fe3O4. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - In recent years, biochar based adsorbents have been given more attention for organic and inorganic pollutants removal. Therefore, in this study, a... 相似文献
1,4-Butanediol has been used as the hydrogen donor in transfer hydrogenation reactions. The equilibrium is driven by the formation of gamma-butyrolactone, and the diol is therefore not required in excess. 相似文献
Twelve new bis-Schiff bases of isatin, benzylisatin and 5-fluoroisatin 3a-3l were prepared by condensation of isatin, benzylisatin and 5-fluoroisatin with primary aromatic amines. The chemical structures of the products were confirmed by 1H- and 13CNMR, IR and mass spectral data. The compounds were screened for antiviral activity against a panel of DNA and RNA viruses. Minimum cytotoxic and minimum virus-inhibitory concentrations of these compounds were determined. Compounds 3c and 3i were the most cytotoxic in HEL cells. These newly synthesized bis-Schiff bases were also tested for their antibacterial and antifungal activities. They did not display activity against S. cerevisiae (ATCC 28383) or C. albicans (CIP 1180-79). 相似文献
As one of the most recently developed membrane separation processes, nanofiltration (NF) has found a number of industrial applications. Ceramic NF membranes are also regarded as the appropriate choice in many applications, due to their higher chemical and physical stability. In this study, the rejection of the chloride ion is investigated using bi-layered γ-Al2O3-TiO2 NF membranes based on α-alumina supports. Compression is used in preparation of the supports and sol-gel dip-coating for the top-layer formation. SEM micrographs, XRD, and nitrogen adsorption/desorption isotherms are used for membrane characterisation. The results show that the calcination temperature (600°C) results in different crystal structures including the brookite phase of TiO2, the γ phase of Al2O3, and a combined phase of aluminium-titanium oxides. The average pore size of the membrane was identified as 1.6 nm using an adsorption/desorption isotherm. The rejection was also studied for the chloride ion, using a cross-flow filtration module. Filtration tests were carried out under different pressures, pH values, and salt concentrations; these showed a smoother behaviour particularly around the isoelectric points (IEPs) due to the dual-layer structure, with the best rejection at pH of approximately 5. 相似文献