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Raman Optical Activity and Raman Spectra of Amphetamine Species--Quantum Chemical Model Calculations and Experiments

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American Journal of Analytical Chemistry 2012年第6期3卷 410-421页

作者： rolf willestofte berg Irene Shim Peter Cyril White Salim Abdali Department of Chemistry Technical University of DenmarkLyngbyDenmark ReForensics LincolnUK Biophysical Chemistry Group Department of ChemistryH.C.Orsted Inst.University of CopenhagenCopenhagenDenmark

Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT-molecular orbital calculations by use of the Gaussian 03W program, based on complete geometry minimizations of the conformational energy of the S-(+)-amphetamine molecule, the S-(+)-amphetamine-H+ ion, and the R-(–)-amphetamine molecule. Following this, harmonic frequency calculations have been made, providing information about the cation vibrational bands, expected in salts of single anions (chlorides) as well as in salts of anions with internal bonds (sulfates, hydrogen phosphates, etc.). It shows that the kind of anion should be given better attention, as so far it has often not been the case, when the spectra are employed for identification purposes. The DFT calculations show that the most stable conformations are those allowing for close contact between the aromatic ring and the amine hydrogen atoms. The internal rotational barrier within the same amphetamine enantiomer has a considerable influence on the Raman and ROA spectra. As predicted the experimental ROA spectra were found to depend on the chirality. Two street samples, provided by the London Police, were also measured and compared to the calculated ROA spectra. The street samples were found to contain different enantiomers of the protonated amphetamine-H+ sulfate. According to the present study the AMPH+ ion in aqueous sulfate solution seems to adopt a conformation in which the phenyl and ammonium groups are in transpositions, similar to what has been found in the solid state.

关键词： Amphetamine Raman ROA DFT Molecular Orbital Drugs Forensic

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Seed selections for crystallization of calcium phosphate for phosphorus recovery

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Journal of Environmental Sciences 2007年第5期19卷 591-595页

作者： SONG Yong-hui Dietfried DONNERT Ute berg Peter G. WEIDLER rolf NUEESCH Chinese Research Academy of Environmental Sciences Beijing 100012 China Institute for Technical Chemistry-Section of Water- and Geo-technology （ITC-WGT） Research Centre of Karlsruhe Karlsruhe D-76021 Germany

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.

关键词： crystallization seed phosphorus recovery Juraperle Apatite

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Tailoring Properties of Biocompatible PEG-DMA Hydrogels with UV Light

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Materials Sciences and Applications 2012年第6期3卷 425-431页

作者： Sania Backstrom Juana Benavente rolf W.berg Karin Stibius Marianne S.Larsen Henrik Bohr Claus Hélix-Nielsen The Biomimetic Membrane Group DTU PhysicsTechnical University of DenmarkLyngbyDenmark Aquaporin A/S Ole Maaloes Vej 3CopenhagenDenmark Grupo de Caracterización Electrocinética en Membranas e Interfases Departamento de Física Aplicada IFacultad de CienciasUniversidad de MálagaMálagaSpain DTU Chemistry Technical University of DenmarkLyngbyDenmark Quantum Protein Center DTU PhysicsTechnical University of DenmarkLyngbyDenmark

Hydrogels are highly water-absorbent hydrophilic polymer networks, which show potential in many biocompatible applications. In previous work, we demonstrated the feasibility of using poly(ethylene glycol) dimethacrylate (PEG-DMA) gels polymerized with a photoinitiator for encapsulation and stabilization of painted biomimetic membrane arrays for novel separation technologies or biosensor applications. These gels were formed from PEG-DMA monomers suspended in phosphate buffered saline (PBS) solution and gelated by radical polymerization in the presence of the photoinitiator Darocur 1173. In this work, we show that the properties of a PEG-DMA hydrogel formed by photoinitiated polymerizetion can be tailored by varying the photocrosslinking time. Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy (RS) showed that the optimal crosslinking time for the gel was 6 - 10 minutes and that the water content of the gels could be tuned in the range of 50 - 90 wt%. The resistivity was between 0.8 - 3.5 Ωm, which is comparable to that of PBS. The low resistivity of the gel makes it compatible for encapsulating membranes for (ion channel based) biosensor applications. With FTIR and RS we identified spectral features of the hydrogel, which may serve as a diagnostic tool to monitor changes in the gels due to variation in parameters such as time, pH, temperature, aging or exposure to chemicals or biological material.

关键词： Hydrogel Swelling UV-Induced Polymerization FTIR Raman Spectroscopy Impedance Spectroscopy

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