Pharmacy Study Material

Free pharmacy material Spectrophotometry-UV/Visible Spectroscopy INTRODUCTION Spectrophotometric techniques are mainly based on the measurement of interaction of electromagnetic radiation with the quantised matter at specific energy levels. In general terms, spectrophotometry is the measurement and interpretation of electromagnetic radiation absorbed when the molecules of a sample move from one energy state to another energy state (i.e., from ground state to excited state (or) exited state to ground state). Electromagnetic waves are usually described in terms of (a) wavelength (λ), the distance between two successive peaks; (b) wave number ( v ), the number of waves per centimetre; frequency ( v ), the number of waves per second. Waves Phenomenon The arithmetic relationship of these three quantities is expressed by the following: c = λ v The laws of quantum mechanics may be applied to photons to show that E = hv where E is the energy of ...