Mass Spectrometry:
In this course, you have so far learnt about a number of spectroscopic methods and their analytical applications. You would have understood through now that besides quantitative analysis, one significant aspect of the spectroscopic methods is which they help in structure elucidation of the molecules being analysed. In the context of structure determination we take up mass spectrometry in this unit. The mass spectrometry is not a spectroscopic method in true sense of the word because here we do not make use of any electromagnetic radiation; yet it is no less significant. In mass spectrometry we study the consequences of bombardment of the analyte in vapour phase with high energy electrons.
We will begin the unit by explaining the principle of mass spectrometry, describe a typical mass spectrum and discuss its characteristics. The discussion on the information available from the mass spectrum will be followed by a detailed account of the instrumental components of mass spectrometers. We will then discuss different applications of mass spectrometry.
Objectives
After studying this unit, you should be able to:
- Elaborates the principle behind mass spectrometry,
- Distinguish mass spectrometry from other spectrometries,
- Describe and explain the terms like base peak, molecular ion, fragments, etc.,
- Elaborates the importance of [M+1] +. and [M+2] +. ion peaks,
- Define the molecular formula of the compound on the basis of its mass spectrum,
- Recognize the common fragmentation patterns in the mass spectra and interpret them to make preliminary leads into the structure of the molecule,
- Outline the necessary components of a mass spectrometer,
- Enlist various methods of ionisation and explain the principle behind them,
- Elaborates several fragmentation types and the factors affecting them, and
- Describes various applications of mass spectrometry.