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12 Spectroscopic techniques: I Spectrophotometric techniques


A. HOFMANN

12.1 Introduction
12.2 Ultraviolet and visible light spectroscopy
12.3 Fluorescence spectroscopy
12.4 Luminometry
12.5 Circular dichroism spectroscopy
12.6 Light scattering
12.7 Atomic spectroscopy
12.8 Suggestions for further reading

12.1 INTRODUCTION


Spectroscopic techniques employ light to interact with matter and thus probe certain
features of a sample to learn about its consistency or structure. Light is electromag-
netic radiation, a phenomenon exhibiting different energies, and dependent on that
energy, different molecular features can be probed. The basic principles of interaction
of electromagnetic radiation with matter are treated in this chapter. There is no
obvious logical dividing point to split the applications of electromagnetic radiation
into parts treated separately. The justification for the split presented in this text is
purely pragmatic and based on ‘common practice’. The applications considered in this
chapter use visible or UV light to probe consistency and conformational structure of
biological molecules. Usually, these methods are the first analytical procedures used
by a biochemical scientist. The applications covered in Chapter 13 present a higher
level of complexity in undertaking and are employed at a later stage in biochemical or
biophysical characterisation.
An understanding of the properties of electromagnetic radiation and its interaction
with matter leads to an appreciation of the variety of types of spectra and, conse-
quently, different spectroscopic techniques and their applications to the solution of
biological problems.

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