Spectroscopy instrumentation

Hendra P J, Jones C and Warnes G 1991 Fourier Transform Raman Spectroscopy Instrumentation and Chemical Applications (New York Ellis HonA/ood)... 

P. Hendra, C. Jones, and G. Wames, Fourier Transform Raiman Spectroscopy Instrumentation and Chemical Applications Fills Horwood, New York, 1991. 

Use is made of colour changes resulting from reaction of pollutant and chemical reagents colour intensity indicates concentration of pollutant in the sample. Reaction can take place in solution or on solid supports in tubes or on paper strips, e.g. litmus or indicator paper. Quantitative assessment of colour formation can also be determined using visible spectroscopy. Instruments are calibrated... 

Since there are a large number of different experimental laser and detection systems that can be used for time-resolved resonance Raman experiments, we shall only focus our attention here on two common types of methods that are typically used to investigate chemical reactions. We shall first describe typical nanosecond TR spectroscopy instrumentation that can obtain spectra of intermediates from several nanoseconds to millisecond time scales by employing electronic control of the pnmp and probe laser systems to vary the time-delay between the pnmp and probe pnlses. We then describe typical ultrafast TR spectroscopy instrumentation that can be used to examine intermediates from the picosecond to several nanosecond time scales by controlling the optical path length difference between the pump and probe laser pulses. In some reaction systems, it is useful to utilize both types of laser systems to study the chemical reaction and intermediates of interest from the picosecond to the microsecond or millisecond time-scales. 

The Mossbauer spectroscopy cell used in this investigation has been described in detail elsewhere (9). The Mossbauer spectroscopy instruments and the fitting routine used are also described elsewhere (9). All isomer shifts are reported relative to metallic iron at room temperature. 

J.P. Coates, Vibrational Spectroscopy Instrumentation for Infrared and Raman Spectroscopy , Appl. Spectrosc. Rev., 33(4), 267 25 (1998). 

This metho dology was previously successfully used for express on-line analyses of phosphate ores. The commercial TRACER 2100 Laser Element Analyzer, a laser-induced breakdown spectroscopy instrument, was utilized for rapid analyses of phosphate ores at the mine site (Rosenwasser et al. 2001). Excellent calibrations were achieved for P and Mg with correlation coefficients significantly above 0.98. The instrument demonstrated strong potential of the LIBS for use in on-site, real-time or grading. LIBS apparatus was developed for ap-... 

Dramatic improvements in instrumentation (lasers, detectors, optics, computers, and so on) have during recent years raised the Raman spectroscopy technique to a level where it can be used for species specific quantitative chemical analysis. Although not as sensitive as, for example IR absorption, the Raman technique has the advantage that it can directly measure samples inside ampoules and other kinds of closed vials because of the transparency of many window materials. Furthermore, with the use of polarization techniques, one can derive molecular information that cannot be obtained from IR spectra. Good starting references dealing with Raman spectroscopy instruments and lasers are perhaps [34-38]. 

Experimental fluorescence- and Fourier-transform-Raman spectroscopy instrumentation... 

Atomic absorption spectroscopy instrumentation can conveniently be considered under the following subheadings. 

Measurements either from the ground or from satellites have been a major contribution to this effort, and satellite instruments such as LIMS (Limb Infrared Monitor of the Stratosphere) on the Nimbus 7 satellite (I) in 1979 and ATMOS (Atmospheric Trace Molecular Spectroscopy instrument), a Fourier transform infrared spectrometer aboard Spacelab 3 (2) in 1987, have produced valuable data sets that still challenge our models. But these remote techniques are not always adequate for resolving photochemistry on the small scale, particularly in the lower stratosphere. In some cases, the altitude resolution provided by remote techniques has been insufficient to provide unambiguous concentrations of trace gas species at specific altitudes. Insufficient altitude resolution is a handicap particularly for those trace species with large gradients in either altitude or latitude. Often only the most abundant species can be measured. Many of the reactive trace gases, the key species in most chemical transformations, have small abundances that are difficult to detect accurately from remote platforms. 

A steady-state diffuse reflectance spectroscopy instrument typically includes a broadband fight source, intermediate optics, spatially separated delivery-collection optical fiber probes,77 and a CCD-based grating spectrometer. Frequency-based approaches have also been pursued.78 Correlations between the glucose concentration and the tissue transport scattering coefficient have been observed.77,78... 

Figure 6 The SELDI technology. This type of proteomic analytical tool is a class of mass spectroscopy instrument that is useful in high-throughput proteomic fingerprinting of serum. Using a robotic sample dispenser, 1 p,L of serum is applied to the surface of a protein-binding chip. A subset of the proteins in the sample binds to the surface of the chip. The bound proteins are treated with a matrix-assisted laser desorption and ionization matrix and are washed and dried. The chip, which contains multiple patient samples, is inserted into a vacuum chamber where it is irradiated with a laser. The laser desorbs the adherent proteins and causes them to be launched as ions. The TOF of the ion before detection by an electrode is a measure of the mass-to-charge (m/z) value of the ion. The ion spectra can be analyzed by computer-assisted tools that classify a subset of the spectra by characteristic patterns of relative intensity (adapted from www.evmsdoctors.com).

R. H. Clarke, S. Londhe, W. R. Premasiri, and M. E. Womble, Low-resolution Raman spectroscopy Instrumentation and applications in chemical analysis, J. Raman Spectrosc. 30,827 (1999). 

Dissolved organic carbon (DOC) measurements were obtained on the size-fraction ated concentrates with a PHOTOchem Organic Carbon Analyzer (Sybron, Model E3500) as an indication of the concentration of humic materials in each fraction. DOC values are reported as ppmC (mgL" ) The major cations in each fraction were determined by inductively coupled plasma spectroscopy (Instruments SA, Model JY 86). 

Phase Transformations from Mossbauer Spectroscopi/ INSTRUMENTATION... 

Most chemists are familiar with atomic emission spectroscopic techniques for metal analysis of aqueous solutions and are equally aware that most of these methods cannot be readily applied to non-aqueous samples. In recent years atomic spectroscopy instrumentation has increased in sophistication allowing the analysis of a wide range of samples on a routine basis for metals content using manual or automated methods. This book aims to cover the importance of metal analysis for a range of organic samples. 

Figure 9.6 Elastic and inelastic scattering of incident light by molecules. Rayleigh, elastic scattering Stokes and anti-Stokes, inelastic scattering. (Reproduced from P. Hendra, P.C. Jones, and G. Warnes, Fourier Transform Raman Spectroscopy Instrumentation and Chemical Applications, Ellis Horwood, Chichester, 1991.)...

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