The foundations of
mass spectrometry lie in the work of Thomson and Aston at the Cavendish
Laboratories, Cambridge University. From 1897, the work carried out by
Thomson and his co-workers receive 7 Nobel prizes in Physics and
Chemistry. Thomson's original work on the existence and properties of
canal rays (positive ions) was taken up by Aston and by the end of the
First World War he had demonstrated the existence of several isotopes
of non-radioactive elements. Aston used electrostatic and magnetic
fields to separated isotope ions be their masses and focus them onto a
photographic plate. Over the next few years a number of key names took
up the early development of mass spectrometry, including Dempster,
Herzog, Bainbridge and Nier. By the end of the 1930's mass spectrometry
had become an established technique for the separation of atomic ions
by mass.
In the 1940's the applications of mass spectrometry
began to spread away from the previous mostly academic work into more
practical fields like nuclear isotope enrichment and the analysis of
the components of petroleum. The World's first commercial instrument
became available in 1948 (The MS-2 - marketed by Vickers in Manchester,
England). The MS-2 made use of
EI
ionisation and had an extremely
limited mass range of about 300 Da with a very limited resolution.
In the early 1950's, the fragmentation of small
organic molecules was beginning to be understood, but the mass
spectrometer was still extremely limited by mass and resolution. At
this time,
time-of-flight (TOF)
analysis (Wiley and Maclaren) and
quadruple analysis (Paul) were
conceived. These early instruments were
the forerunners of today's 'cheap' benchtop instruments seen in just
about every chemical, biochemical lab in the world.
The next major development was that of
gas
chromatography and its coupling to mass spectrometry. This allowed,
for
the first time, the analysis of mixtures of analytes without laborious
separation by hand. The development of GC-MS was the trigger for the
development of modern mass spectrometry. In 1956, the first
biologically important molecules were successfully analysed. New
ionisation techniques developed over the last 25 years (
fast particle desorption,
electrospray ionisation and
matrix-assisted laser
desorption/ionsation) have opened up the world of biological
chemistry to mass spectrometry. Just about every compound class can be
analysed by some sort of mass spectrometry (see the
theory section for a description of the
most important techniques) and the present mass records extend well
into the megadalton range.
For an excellent and incredibly extensive history of mass spectrometry,
take a trip to the
Scripps
Research Institute "History of Mass Spectrometry" site.
