Fluorescence and Phosphorescence Spectroscopy

Book excerpt: Fluorescence and Phosphorescence Spectroscopy: Physicochemical Principles and Practice deals with the physicochemical principles and applications of fluorescence and phosphorescence spectroscopy in experimental biology and chemistry. Topics covered include the absorption of light by molecules; instrumentation for the measurement of fluorescence and phosphorescence; solvent and acidity effects on electronic spectra; and polarization of fluorescence and phosphorescence. Comprised of four chapters, this book begins with a discussion on photophysical processes in isolated molecules and molecules in solution, paying particular attention to thermal equilibration of electronically excited molecules, phototautomerism, and coordination by metal ions. The next chapter describes the instrumentation for measuring fluorescence and phosphorescence, which consists essentially of a light source to electronically excite the sample; a monochromator to separate the light of desired energy from the source; a sample compartment; a second monochromator to isolate the sample's fluorescence energy from the excitation energy; a photodetector to translate the fluorescent light into an electrical signal; and a readout system such as a galvanometer or a recorder, coupled with an amplifier to determine the intensity of fluorescent light that is emitted. The final chapter is devoted to various applications of fluorescence and phosphorescence spectroscopy, including the analysis of organic and inorganic compounds. This monograph is written primarily for analytical chemists and biological scientists.