13 —
The Role of Computers and Microprocessors in Analytical Chemistry
13.1—
Introduction
The management of an analytical chemistry laboratory involves a number of different but related
operations. Analysts will be concerned with the development and routine application of analytical
methods under optimum conditions. Instruments have to be set up to operate efficiently, reproducibly
and reliably, sometimes over long periods and for a variety of analyses. Results will need to be recorded
and presented so that the maximum information may be extracted from them. Repetitive analysis under
identical conditions is often required, for instance, in quality assurance programmes. Hence a large
number of results will need to be collated and interpreted so that conclusions may be drawn from their
overall pattern. The progress of samples through a laboratory needs to be logged and results presented,
stored, transmitted and retrieved in an ordered manner. Computers and microprocessors can contribute
to these operations in a variety of ways.
Instrument Optimization
It is rare to find an instrumental method, which, when optimized for the determination of one analyte in
a particular matrix, can then be directly applied to another analyte and matrix. Thus each analyte and
matrix combination will require a different package of instrument settings. The number of parameters
which need to be controlled in this way is often large. For example, in flame atomic absorption
spectrometry it will include the nature of the fuel/support gas mixture, rate of nebulizer feed, optical
alignment, slit-width, monochromator setting, power to lamps and photo-multipliers, and integration
time. The traditional method of dealing with this is to adjust each individual parameter in turn whilst
holding the others constant. A record of the settings is kept and the instrument manually reset when the
analysis is to be repeated at a later time. Computers and microprocessors can help in the initial selection
of most parameters, which are simply entered from a keyboard or keypad, but more particularly by
allowing the storage and recall of groups of settings more quickly and accurately than can be done
manually. Furthermore, greater stability of operation results from the continued monitoring of these
settings. Modern