E-Jurnal Universitas Tunas Husada Tasikmalaya
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Improving desk-based methods for quantifying and enhancing air pollution mitigation by green infrastructure at different scales
No full textModern Raman spectromicroscopy: Some early investigations with deuterated compounds
No full textRaman spectroscopy is used less commonly than other spectroscopic techniques by isotopic chemists. The University of Surrey has recently become a regional centre for the technique following our acquisition of a powerful high-resolution multi-laser Raman spectromicroscope (Renishaw inVia, model RE04, via EPSRC grant EP/M022749/1). This poster reports some early experience with the technique as applied to the analysis of deuterated compounds. The spectrometer is based around Raman scattering from any of five lasers ranging from the ultraviolet to blue, green, red and near infrared (244–785 nm). The sampling beam has an area of just 2-10µm and hence the spectrometer has the ability to automatically scan tiny sample areas, offering the possibility of obtaining Raman imaging for 2-D and (via confocality) even 3-D samples. Investigations into isotopic applications of these multidimensional abilities are in progress. The high resolution of the system also enables excellent spectra to be recorded from very tiny samples, e.g. from a small part of this 200µm crystal of [2H8]naphthalene. The poster provides examples of the following advantages when deuterated compounds are analysed by Raman:Improved sensitivity is available via powerful lasers and digital spectral accumulationRapid generation of high quality one-dimensional Raman spectra from various sample typesLow matrix effects for glass enables direct analysis within ordinary sealed glass lab vialsHigh spectral and spacial resolution provides the ability to work with tiny samples/areasHighly specific results, as vibrational modes can be very sensitive to isotopic substitutionDirect quantitative analysis of isotopic mixtures is possible by selecting the appropriate peaksLow background from silicagel means TLC & HPTLC applications are possibleSurface enhanced Raman spectra (SERS) can be simply obtained via stable silver colloids</p
Melvin Calvin Award Lecture, IIS Symposium, Heidelberg 2012Isotopic Chemistry: the Most Varied of Careers….with Tritium and Deuterium the Most Versatile of the Isotopes.
No full textIsotopic chemistry offers the opportunity for organic chemists to explore a surprisingly large variety of scientific avenues. It lends itself naturally to multidisciplinary research projects and provides the sophisticated tools with which the most complex of processes can be investigated. This Melvin Calvin Award lecture will keep to a broadly chronological theme and will give examples of how the remarkable versatility of the two heavy hydrogen isotopes has been utilised during collaborative studies in areas as varied as: plant and insect biochemistry, drug metabolism and pharmacokinetics, structure determination, NMR spectroscopy, reaction mechanisms, molecular energetics, and novel catalyst development. Few other careers can provide the opportunity to study such varied and fundamental subjects and still provide challenges that are as compelling and exciting some four decades later