ABSTRACT
Spectral analysis or spectroscopy involves the study of the interaction between matter and light at different frequencies; this interaction results in a change of the movement of atoms or molecules in matter, leading to energy transitions. Spectral analysis methods are broadly categorized into three types: absorption spectroscopy, emission spectroscopy, and diffraction spectroscopy. This chapter describes the basic analytical methods: ultraviolet–visible (UV–Vis), infrared (IR), and Raman spectroscopy. UV–Vis spectroscopy involves the study of the interactions between samples and ultraviolet and visible light. Light energy corresponds to electronic transitions. Molecules with various chemical structures can absorb light of different wavelengths and exhibit different electronic transitions, with various possibilities. A UV–Vis spectrometer is employed for recording the UV–Vis spectra of samples, transmittance or absorbance of samples against wavelength. IR spectroscopy involves the study of the interactions between molecules and IR light.
