ABSTRACT
This chapter considers the application of spectroscopic methods for the characterization of naturally occurring pesticides, it would be advantageous to review the essential principles concerning the interaction of radiation with matter. There are a few basic units which are important in order to understand the absorption and emission of radiation. Absorption spectroscopy is widely used for structural investigations of organic compounds while emission spectroscopy provides qualitative information and has only limited use because most organic compounds are not stable to heat or violent electrical excitations. When a molecule absorbs radiation, it must meet two requirements: the incident ray must have the same frequency as a rotational, vibrational, or electronic frequency in the molecule and the molecule must have a permanent dipole or an induced dipole. The radiation produced in cosmic ray region is very powerful and can penetrate through many objects.
