Visible Spectrometry:
Ultraviolet-visible (UV-VIS) spectrometry. This concerns the measurement of the consequences of interaction of EM radiations in the UV and/or visible region with the absorbing species like, atoms, molecules or ions. In such determinations the extent to which radiation energy is absorbed through a chemical system as a function of wavelength, in addition to, absorption at a fixed predetermined wavelength of the radiation is measured. Because such measurements need an instrument known spectrometer the technique is known as UV-VIS spectrometry.
The UV-VIS spectrometry is one of the oldest instrumental method of analysis and is the basis for a number of ideal methods for the determination of micro and semi- micro quantities of analytes in a sample. We will start through understanding the theory behind UV-VIS spectrometry in terms of the origin and the features of the UV-VIS spectrum. Then we will discuss the fundamental principles that form the basis of the analytical applications of UV-VIS spectrometry. It will be followed by an account of the essential components of a UV-VIS spectrometer and their functions. Thereafter, we will discuss the qualitative and quantitative applications of UV-VIS spectrometry in diverse areas. In the next unit you will know about the study of infra- red spectrometry which concerns the interaction of electromagnetic radiation in the infrared region with matter.
Objectives
After studying this unit, you should be able to:
- Elaborates the origin and the characteristics of UV-VIS spectrum,
- Outline various types of species absorbing in the UV-VIS region,
- Elaborates the Lambert's and Beer's laws,
- Describes the factors leading to deviation from Beer-Lambert's law,
- Define the components of UV-VIS instruments,
- State principles of various types of UV-VIS instruments,
- Explain the methodology of quantitative applications of UV-VIS spectrometry, and
- State various applications of UV-VIS spectrometry.