A facile method for preparing molecularly imprinted polymer spheres using spherical silica templates

A novel and facile preparation method for spherical molecularly imprinted polymer (MIP) beads is presented. Two types of beads were synthesized and investigated: (i) silica-MIP composites were obtained by filling spherical, porous C-4-coated silica beads with print molecule and monomers followed by polymerisation; (ii) spherical molecularly imprinted polymer beads were acquired mirroring the silica particles in size, shape and pore structure by removing the silica matrix from the silica-MIP composites. With regard to their chromatographic properties and yield of the materials both types of particle were more advantageous compared to irregularly shaped traditional MIPs. Also the work-up time to obtain imprinted spherical particles is greatly reduced compared to traditional methods using polymer monoliths, which have to be ground, sieved and sedimented. Generally, the described method may open new possibilities for synthesis of novel types of imprinted polymer formats such as membranes, bulk polymers, films or in-situ columns using appropriate support or sacrificial materials

Liquid chromatography and electron-capture dissociation in Fourier transform ion cyclotron resonance mass spectrometry

Liq. sepn. methods in combination with electrospray mass spectrometry as well as the recently introduced fragmentation method electron capture dissocn. (ECD) have become powerful tools in proteomics research. This paper presents the results of the first successful attempts to combine liq. chromatog. (LC) and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) with ECD in the anal. of a mixt. of std. peptides and of a bovine serum albumin tryptic digest. A novel electron injection system provided conditions for ECD sufficient to yield extensive sequence information for the most abundant peptides in the mixts. on the time-scale of the chromatog. sepn. The results suggest that LC/ECD-FTICRMS can be employed in the characterization of peptides in enzymic digests of proteins or protein mixts. and identify and localize posttranslational modifications. [on SciFinder (R)

Application of Molecular Imprinting Technique in Organophosphorus Pesticides Detection

International audienceMolecular imprinting technique offers a means of producing practical materials that are able to recognize a certain molecule in terms of shape, size and chemical functionality. In order to obtain a highly selective recognition of organophosphorus pesticides (OPPs), we synthesized molecularly imprinted polymers (MIPs) using pirimiphos-methyl as the template, methacrylic acid as the monomer and ethylene glycol dimethacrylate as the crosslinker. After polymerization, molecularly imprinted solid-phase extraction (MISPE) was used for the selective preconcentration of OPPs. The preparation methods and synthesis conditions of MIPs were discussed, and the specificity of MIPs and nonimprinted polymers were investigated. The results showed that MIPs enable the selective extraction of pirimiphos-methyl successfully from water sample, and demonstrated the potential of MISPE for selective and cost-effective sample pretreatment

THE FE-54,FE-56)(N, P) MN-54,MN-56 REACTIONS AT E(N)=97 MEV

Double-differential cross sections of the Fe-54,Fe-56(n, p) reactions have been measured at 97 MeV in the angular range 0-30-degrees for excitation energies up to 40 MeV. The spectra have been decomposed into different multipolarities by a technique based on the use of sample angular distributions calculated within the distorted-wave Born approximation. From the identified Gamow-Teller strength, S(beta)+ values were obtained for Fe-54 Fe and Fe-56. Comparisons with available shell-model calculations of the GT strength were made. The results are important for models of supernova explosions since electron-capture rates, which are proportional to S(beta)+, in 1f2p-shell nuclei affect the dynamics of the star. At higher excitation energies, the spectra are dominated by L = 1 strength in broad distributions with a maximum at about 12 MeV. Microscopic calculations based on the random-phase approximation were performed and compared with the experimental data