Sector instruments for chemical analysis and research

Abstract

When the last chemical elements were successfully measured by mass spectrometry its use for the characterisation of isotopes declined, but its use for chemical analysis and research grew. This new field of activity was aided by the emergence of commercially manufactured sector mass spectrometers designed for the analysis of oil refinery gases. Although the 1940s saw the use of mass spectrometry dominated by the petroleum industry it also saw many developments in its application to chemical analysis. By the early 1950s heated inlet systems were allowing spectra of all kinds of volatile organic compounds to be obtained. The 1950s saw the development of accurate mass measurement of organic molecules as a means of determining their elemental composition. This led to a demand for higher resolution double focusing instruments. Two types of design competed for this application, each with their perceived advantages and disadvantages. It was another decade, following the application of computers to high throughput accurate mass measurement, before one of these came to dominate. Double focusing sector instruments also enhance the information afforded by “metastable” ions, allowing identification of precursor and product ions. This led to the developments of Collision Induced Decompositions, MIKES and “linked scans”. The mass range demanded of mass spectrometers jumped to new levels with the development of Fast Atom Bombardment (FAB). This led to new sector designs incorporating innovative new magnets. The success of FAB as a soft ionisation technique meant it produced little fragmentation and structural information. This led to a growth in the use of tandem MS/MS instrumentation as a tool for determining structures. This paper recounts these and many other developments which kept magnetic sectors at the centre of major new developments in mass spectrometry for chemical analysis and research for so long.