Spectroscopic techniques instrument modules

Section I covers the more conventional equipment available for analytical scientists. I have used a unified means of illustrating the composition of instruments over the five chapters in this section. This system describes each piece of equipment in terms of five modules - source, sample, discriminator, detector and output device. I believe this system allows for easily comparing and contrasting of instruments across the various categories, as opposed to other texts where different instrument types are represented by different schematic styles. Chapter 2 in this section describes the spectroscopic techniques of visible and ultraviolet spectrophotometry, near infrared, mid-infrared and Raman spectrometry, fluorescence and phosphorescence, nuclear magnetic resonance, mass spectrometry and, finally, a section on atomic spectrometric techniques. I have used the aspirin molecule as an example all the way through this section so that the spectral data obtained from each... 

Fluorescence is unique among spectroscopic techniques due to its inherently multidimensional nature, the emission process containing a wealth of orthogonal information that is related to the fluorophore and its surroundings. Time- and frequency-domain fluorescence methods are instrumentally sophisticated, but they improve both the sensitivity and selectivity of fluorimetry. Any dye that is used for steady-state fluorescence detection can be used for time-resolved detection as well. Most of these fluor-ophores display lifetimes from 1 to 10 ns, which requires fast electronics for time-domain lifetime measurements or modulation frequencies from 10... 

Since the discovery of the photoacoustic (PA) effect by Bell in 1880, who used the Sun as radiation source, a foot-operated chopper for modulation and an earphone as acoustic detector, the PA effect has found numerous applications as a sensitive and rather simple technique for determining optical, thermal and mechanical properties of all kinds of samples. This article focuses on methods and instrumentation employed in spectroscopic applications. Since photothermal (PT) spectroscopy is discussed elsewhere in the encyclopedia, PT schemes are only briefly mentioned here, whereas emphasis is put on instrumentation used in photoacoustic spectroscopy. 

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