Page 22 - Tandem Techniques

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by analysis followed by synthesis, using the very primitive techniques already mentioned. Such was the
caliber of the early twentieth century analysts who, with grossly inferior tools, laid the foundations of
modern chemistry.

The analytical instrument industry became firmly established in the late 1940s and early 1950s,
provoked by the technological advances that took place during the Second World War. Some of the first
instruments to appear on the industrial scene were the polarograph, various types of pH meters and the
manually operated UV spectrometer. This was the first time that reliable, and generally affordable
scientific measuring equipment was available to universities and industry. In the mid 1950s the
scanning UV spectrometer was introduced, and this was rapidly followed by the scanning IR dispersion
spectrometer. At this time the mass spectrometer, the nuclear magnetic resonance spectrometer (NMR)
and the X-ray crystallograph were still novelties in the laboratories of academia. In the mid 1950s the
technique of gas chromatography (GC) was invented by James and Martin [1], and in the late 1950s the
first isothermal gas chromatograph was produced. Excluding the rather massive and cumbersome Craig
Machine, that was used largely in preparative LLC, the gas chromatograph was the first analytical
separation instrument to be developed, despite the fact that liquid chromatography had been known
since the latter part of the nineteenth century. The pre-eminence of GC was partly due to the nature of
the technique, and partly due to the fact that it was at a more advanced stage of development, and was
far easier to automate than LC.

In the early 1960s the first effective mass spectrometers began to appear in conjunction with the first
low-resolution 60 kHz NMR machines. During this period, the GC instrument was further updated to
include temperature programming, and the first primitive liquid chromatographs began to make their
appearance. The 1970s were the heyday of analytical instrument development, spurred on by the
introduction of the mini and then the micro computers. Fourier transform IR and NMR machines were
introduced with consequent impressive increases in resolution and sensitivity. Liquid chromatographs
were fitted with versatile gradient