Raman Articles

Raman Microscopy for Detecting Counterfeit Drugs — A Study of the Tablets Versus the Packaging

With the increasing proliferation of counterfeit drug products, there is an incentive to screen drugs for legitimacy. One method is to examine the tablet itself, which is usually a destructive operation. Another method that has been explored is to characterize the packaging, which enables nondestructive screening of the product. Raman microscopy has been found to be a useful tool, and it is often the tool of choice for these measurements.

Published in Spectroscopy, June 2014

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Practical Group Theory and Raman Spectroscopy, Part II: Application of Polarization

In this second installment of a two-part series we present polarized Raman spectra and discuss the association of the symmetry species of the normal vibrational mode and the depolarization ratio of Raman scattering. We discuss those aspects of molecular symmetry and Raman polarization rules that can be applied with normal Raman instrumentation. Materials include liquids, single crystals, and polycrystalline compounds.

Published in Spectroscopy, March 2014

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Practical Group Theory and Raman Spectroscopy, Part I: Normal Vibrational Modes

Group theory is an important component for understanding the fundamentals of vibrational spectroscopy. The molecular or solid state symmetry of a material in conjunction with group theory form the basis of the selection rules for infrared absorption and Raman scattering. Here we investigate, in a two-part series, the application of group theory for practical use in laboratory vibrational spectroscopy.

Published in Spectroscopy, February 2014

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Considerations of Grating Selection in Optimizing a Raman Spectrograph

The performance of a Raman spectrograph for a particular application will depend, among other things, on its sensitivity and spectral resolution. The sensitivity will determine how long it will take to record a spectrum with a given signal-to-noise ratio.

Published in Spectroscopy, October 2013

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Raman Imaging of Silicon Structures

Here we examine what is commonly called a Raman image and discuss how it is rendered. We consider a Raman image to be a rendering as a result of processing and interpreting the original hyperspectral data set.

Published in Spectroscopy, September 2013

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Resonance Enhancement of Raman Spectroscopy: Friend or Foe?

The presence of electronic transitions in the visible part of the spectrum can provide enormous enhancement of the Raman signals, if these electronic states are not luminescent. In some cases, the signals can increase by as much as six orders of magnitude.

Published in Spectroscopy, June 2013

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Raman for Oil Shale Exploration

Discussion and examples of the practical application of Raman micro-spectroscopy for the analysis of materials directly related to oil shale exploration.

Published in Spectroscopy, March 2013

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Raman Microscopy Analysis of Molecular Orientation in Organic Fibres

The processes involved in creating fibers from organic polymers - either man-made or natural - have the potential to orient the molecules in the fibres.  Examination of a number of fibres confirms that orientation is a more or less ubiquitous phenomenon that can be detected and quantified by Raman microscopy.

Published in Spectroscopy, February 2013

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From Micro– to Macro–Raman Spectroscopy:Solar Silicon for a Case Study

The paper explains the use of the Raman spectroscopy to the stress analysis in Silicon based panel solar materials.

Published by InTech Advanced Aspects of Spectroscopy as a chapter of a book "Advanced Aspects of Spectroscopy"., 2012.

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Multivariate data processing of spectral images: The Ugly, the Bad and the True

The paper demonstrates the difference between 'pretty' and 'true' Raman chemical images, and how to achieve true and pretty Raman chemical images.

Published in Spectroscopy, August 2007

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Raman Imaging: Defining the Spatial Resolution of the Technology

Chemical images of polystyrene beads on silicon acquired using Raman mapping and image processing are reviewed. The effects of the objective on the quality of the final image, particularly its magnification and numerical aperture, and the step size of the map, are discussed as well.

Published in Spectroscopy, supplement Raman, June 2006

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Spectroscopic imaging for the life sciences - more than just a pretty picture

It has long been a major goal of scientists to understand the many complex processes taking place within living organisms, ranging from microscopic species such as bacteria and viruses at one extreme, through to the human at the other. This article shows that micro-spectroscopic imaging is a key technique for biological research.

Published in Spectroscopy Europe Life Science supplement, August/September 2005

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Spectroscopy Solutions for Materials Analysis

Raman and EDXRF Chemical Imaging for Formulation Process Development and Quality Control Compounds of magnesium and calcium are common components of pharmaceutical formulations.

Spectroscopic imaging can provide a complete understanding of a formulation. This paper compares two spectral imaging techniques - energy dispersive X-Ray Fluorescence (EDXRF) microscopy and Raman microscopy.

Published in Spectroscopy, June 2005

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Biopharma Imaging and Analysis

Advancing Towards a More Detailed Picture of Chemistry

There is a wealth of analytical and imaging techniques available for the measurement of biopharma samples. The samples themselves can be wide ranging and take numerous forms: single cells, tissues, crystals or blended formulations. To study and develop such samples many techniques, including fluorescence microscopy, NIR imaging, AFM and SEM, have been used. Published in European Biopharmaceutical Review, Spring 2005

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Refined Raman Spectroscopy

Bringing new insight into industrial processes

Fibre probes and ease of use make Raman spectroscopy systems attractive for monitoring process control in many industries, ranging from pharmaceuticals to petrochemicals. The authors describe the Raman effect and discuss systel and monitoring basics.

Published in Optics & Photonics News, June 05

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A new dimension in cell imaging

Combining chemical and spatial information

There are many microscopic imaging techniques used to investigate the complexities of cell structure, including optical microscopy, confocal laser scanning microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). These techniques provide highly detailed images of the cells, but they fail to characterize the chemistry and composition of the sample under examination. Spectroscopic techniques, however, can do just that, and in particular Raman micro-spectroscopy is fast becoming established for probing cellular biochemistry on the micron scale.

Published in BIOforum Europe, April 2005

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Micro-spectroscopy - shedding light on rock formation

Whilst there are many imaging techniques available to a research scientist, the information which is provided is often only of a visual/topographical nature. What they fail to provide is true compositional (chemical/elemental) analysis of the materials. However, microspectroscopic techniques such as Raman or X-Ray Fluorescence (XRF) can fill this gap, allowing highly detailed images to be generated based upon the sample's material composition.

 Published in Spectroscopy Europe, June 2005

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