Pharmaceutical Analysis

Chapter 8

Electron Spin Resonance Spectroscopy

INTRODUCTION

The ESR technique was first developed by Zavoisky in 1944. The ESR is frequently called as electron paramagnetic resonance spectroscopy and electron magnetic resonance spectroscopy. This is an absorption spectroscopy in which radiation of microwave frequency is absorbed by paramagnetic substances. This method is mainly used to detect the compounds with the unpaired electrons. These measurements are mainly helpful in the study of the relationship between the energy differences and the absorption of the electromagnetic radiation. In this method, the spin is said to be intrinsic property of the electrons given by the quantum number ½.

The basic theory and instrumentation of ESR is similar ...