Page 21 - Tandem Techniques

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Chapter 1
Introduction To Tandem Techniques

The Evolution of Analytical Instruments

In the early days of chemical analysis, analytical procedures were carried out sequentially, not
concurrently, and consequently were very time consuming. Furthermore, the techniques to choose from
were few in number, very crude in nature, and demanded considerable skill on the part of the analyst.
At the beginning of the twentieth century, distillation, filtration and crystallization were the only
separation techniques that were practical. Identification was achieved by employing such measurements
as boiling points, melting points, vapor pressures and refractive indices; for quantitative evaluation, the
analyst could only resort to gravimetric and volumetric procedures.

Fifty years ago analytical instruments as we know them today were virtually non-existent. The Abbe
Refractometer, some crude pH meters, a manually operated UV spectrometer and a carbon-hydrogen-
nitrogen analyzer (often constructed in the laboratory) comprised the limit of instrument availability. At
the beginning of this century the structure of some fairly complex organic compounds had been
elucidated, including such substances as morphine, vitamin C, thyroxin etc. These relatively complex
structures were determined in the classical manner of that time,