Raman spectroscopy overview

The third important source for infonnation on modem Raman spectroscopy are the books cataloguing the proceedings of the International Conference on Raman Spectroscopy (ICORS) [37]. ICORS is held every two years at various international locations and feahires hundreds of contributions from leading research groups covering all areas of Raman spectroscopy. Although the published presentations are quite limited in lengdi, they each contain references to the more substantial works and collectively provide an excellent overview of current trends m Raman spectroscopy. A snapshot or brief sununary of the 1998 conference appears at the end of this chapter. 

The historical development and elementary operating principles of lasers are briefly summarized. An overview of the characteristics and capabilities of various lasers is provided. Selected applications of lasers to spectroscopic and dynamical problems in chemistry, as well as the role of lasers as effectors of chemical reactivity, are discussed. Studies from these laboratories concerning time-resolved resonance Raman spectroscopy of electronically excited states of metal polypyridine complexes are presented, exemplifying applications of modern laser techniques to problems in inorganic chemistry. 

The goal of this chapter will be to provide an overview of the use of planar, optically resonant nanophotonic devices for biomolecular detection. Nanophotonics23 24 represents the fusion of nanotechnology with optics and thus it is proposed that sensors based on this technology can combine the advantages of each as discussed above. Although many of the issues are the same, we focus here on optical resonance rather than plasmonic resonance (such as is used in emerging local SPR and surface-enhanced Raman spectroscopy-based biosensors). 

Via NMR and Raman spectroscopy, we can measure the solid hydrate phase. Although an overview of such spectroscopy measurements is provided in Section 6.2, some of the important results for hydrate properties in comparison to ice are provided here. 

Table 6.3 provides a summary of the different microscopic techniques that have been applied to hydrate studies and the type of information that can be obtained from these tools. The following discussion provides a brief overview of the application of diffraction and spectroscopy to study hydrate structure and dynamics, and formation/decomposition kinetics. For information on the principles and theory of these techniques, the reader is referred to the following texts on x-ray diffraction (Hammond, 2001), neutron scattering (Higgins and Benoit, 1996), NMR spectroscopy (Abragam, 1961 Schmidt-Rohr and Spiess, 1994), and Raman spectroscopy (Lewis and Edwards, 2001). 

A variety of other excellent texts are available for in-depth review of the fundamentals of Raman spectroscopy, including core technologies and applications [2, 3]. This is intended as a very brief, non-rigorous overview for non-spectroscopists who may be unfamiliar with the principles of Raman, its strengths, and practical limitations. For discussion of the experimental details of variant techniques such as ROA (Raman optical activity) or SERS, the reader is directed to the appropriate chapters in this text. 

This chapter discusses the use of Raman spectroscopy for analysis of biofluids, specifically blood and urine. After a brief overview of the clinical motivations for analyzing biofluids, the benefits of optical approaches in general and Raman spectroscopy in particular are presented. The core of the chapter is a survey of equipment, data-processing, and calibration options for extracting concentration values from Raman spectra of biofluids or, in the in vivo cases, volumes that include biofluids. The chapter finishes with a discussion of fundamental limits on how accurately concentrations can be determined from Raman measurements and how closely current experiments approach that limit. 

Sample variability is a critical issue in prospective application. For optical technologies, variations in tissue optical properties such as absorption and scattering coefficients can create distortions in measured spectra. This section provides a brief overview of techniques to correct turbidity-induced spectral and intensity distortions in fluorescence and Raman spectroscopy, respectively. In particular, photon migration... 

II. OVERVIEW OF VIBRATIONAL DEPHASING AND COHERENT RAMAN SPECTROSCOPY... 

Patel BD, Mehta PJ (2010) An overview application of Raman spectroscopy in pharmaceutical field. CurrPharm Anal 6(2) 131-141... 

Micro-Raman spectroscopy (pRS) involves acquiring spatially resolved Raman spectra by combining the conventional Raman spectrometer with a microscopic tool, typically an optical microscope. This chapter introduces the basic methodology of micro-Raman spectroscopy and presents an overview of its application to organic and inorganic nanostructures using specific examples from literature. 

A NIR-laced article by Heise et al. discusses the technologies used in noninvasive glucose monitoring [167]. In this article, he describes his own work with a FT-NIR instrument, but also provides a nice overview of other NIR applications plus luminescence, optical activity, and Raman spectroscopy. He gives 38 references on these topics. 

Since the objective of the studies described herein is the characterisation of the solute species formed following redox reaction the very extensive research dealing with characterisation of the electrode/solute interface will not be discussed, excellent overviews of the experimental aspects of this subject are available. While this contribution focuses on applications involving IR, Raman spectroscopy has proved to be invaluable to many SEC studies where surface-enhanced Raman spectroscopy (SERS) and resonance Raman spectroscopy dominate. Reviews and recent studies attest to the value of these approaches. ... 

Vandenabeele, P., and L. Moens. 2005. Overview Raman Spectroscopy of pigments and dyes. In... 

Vandenabeele, P., and L. Moens. 2005. Overview Raman spectroscopy of pigments and dyes. In Raman Spectroscopy in Archaeology and Art History, G. M. Edwards Howell, and John M. Chalmers (eds.), pp. 71-83. London Royal Society of Chemistry. 

UP Agarwal. An Overview of Raman Spectroscopy as Applied to Lignocellulosic Materials. In DS Argyroponlos, ed. Advances in Lignocellulosics Characterization. Atlanta TAPPI Press, 1999, pp. 201-225. 

We have made direct optical observations and measmements of microbial activity at various pressures. As in the above experiments, we have used diamond anvil cells in combination with micro-Raman spectroscopy and optical microscopy to directly monitor their viability and metabolic activity at extreme conditions [58]. The following is an overview of these direct observations of microbial activity under extreme pressures and their implications for adaptive mechanisms of life (as we know it) on this planet. 

In the development of zeolite science, infrared spectroscopy has been one of the major tools for structure and reactivity characterization. However, the field of zeolite Raman spectroscopy is gaining importance. The Raman effect is an intrinsically weak phenomenon, and Raman spectra of zeolites are often obscured by a broad fluorescence. Just like IR spectroscopy, Raman can detect small. X-ray amorphous zeolite particles. Therefore, Raman spectroscopy has been used to examine zeolite synthesis mixtures with ex-situ methods (with separation of solid and liquid) and in-situ methods. In this work we give an overview of the zeolite framework vibrations, zeolite synthesis, adsorption on zeolites and metal substitution and ion exchange in zeolites. 

Physicochemical properties of carbon materials are investigated by means of various spectroscopic techniques, such as infrared (IR), X-ray photoelectron pCPS), electro spin resonance (ESR), or Raman spectroscopy (RS). These techniques provide very useful qualitative information about the carbon surfaces. A detailed discussion of the procedures and instruments used in these techniques is outside the scope of this chapter a brief overview is presented, to highlight the importance of the use of spectroscopic techniques to illustrate the carbon surface functionalities and to compare the results that arise from a consortium of methods. 

Spectroscopic methods can provide fast, non-destructive analytical measurements that can replace conventional analytical methods in many cases. The non-destructive nature of optical measurements makes them very attractive for stability testing. In the future, spectroscopic methods will be increasingly used for pharmaceutical stability analysis. This chapter will focus on quantitative analysis of pharmaceutical products. The second section of the chapter will provide an overview of basic vibrational spectroscopy and modern spectroscopic technology. The third section of this chapter is an introduction to multivariate analysis (MVA) and chemometrics. MVA is essential for the quantitative analysis of NIR and in many cases Raman spectral data. Growth in MVA has been aided by the availability of high quality software and powerful personal computers. Section 11.4 is a review of the qualification of NIR and Raman spectrometers. The criteria for NIR and Raman equipment qualification are described in USP chapters <1119> and < 1120>. The relevant highlights of the new USP chapter on analytical instrument qualification <1058> are also covered. Section 11.5 is a discussion of method validation for quantitative analytical methods based on multivariate statistics. Based on the USP chapter for NIR <1119>, the discussion of method validation for chemometric-based methods is also appropriate for Raman spectroscopy. The criteria for these MVA-based methods are the same as traditional analytical methods accuracy, precision, linearity, specificity, and robustness however, the ways they are described and evaluated can be different. 

Application of Raman spectroscopy to zeolite research was, for a long time, hampered by severe problems due to fluorescence phenomena. These could be overcome during the recent past (cf. Sect. 4.4 and [229]). Meanwhile, IR and Raman results of zeolite investigation, as reported in the literature are so muner-ous that an exhaustive overview would be beyond the frame of the present chapter [compare, therefore, also earlier reviews such as those by Yates [230], Ward [231], Baker et al. [232] (especially for Fourier transform far-infrared spectroscopy), Foerster [233] and Karge et al. [234]. However, in the following subsections many examples will be provided which are meant to demonstrate the high potential of IR, Raman spectroscopy and INS for the characterization of zeofites and related systems. 

This chapter gives a brief overview of IR and Raman spectroscopy, with examples from a number of application areas, demonstrating the usefulness of both techniques in the pharmaceutical laboratory. In general, these examples will be grouped by application, rather than by technique, since the two should ideally be used together, in conjunction with other analytical techniques, in a problem-driven manner. 

For a comprehensive overview of Raman spectroscopy fundamentals, theory, and applications, see (a) McCreery, R. L. in Chemical Analysis Vol 157, Wmefordner J. D, Ed. Wiley New York, 2000. (b) Lewis, I. R. Edwards, H. G. M. Handbook of Raman Spectroscopy, Erom the Research Laboratory to the Process Line Marcel Dekker New York, 2001. (c) Pivonka, D. E. Chalmers, J. M. Griffiths, R R. Eds. Applications of Vibrational Spectroscopy in Pharmaceutical Research and Development WUey New York, 2007. (d) Dollish, F. R. Fateley, W. G. Bentley, F. F. Characteristic Raman Frequencies of Organic Compounds Wiley New York, 1974. 

Although Raman spectroscopy does not employ absorption of infrared radiation as its fundamental principle of operation, it is combined with other infrared spectroscopies into a joint section. Results obtained with various Raman spectroscopies as described below cover vibrational properties of molecules at interfaces complementing infrared spectroscopy in many cases. A general overview of applications of laser Raman spectroscopy (LRS) as applied to electrochemical interfaces has been provided [342]. Spatially offset Raman spectroscopy (SORS) enables spatially resolved Raman spectroscopic investigations of multilayered systems based on the collection of scattered light from spatial regions of the samples offset from the point of illumination [343]. So far this technique has only been applied in various fields outside electrochemistry [344]. Fourth-order coherent Raman spectroscopy has been developed and applied to solid/liquid interfaces [345] applications in electrochemical systems have not been reported so far. 

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