It is of great practical importance to develop simple methods for the
automatic detection ofthe controlled state of the analytical method
being applied. The key point is to find quantities that greatly affect
the quality of the analytical results and that can be easily estimated
during the measurement process from the measured data. The
signal-to-noise ratio has proved to be such a quantity in gas
chromatographic methods. The statistical properties of the
estimation of the signal-to-noise ratio from gas chromatographic
data have been investigated. The suggested practical method for
estimating the signal-to-noise ratio proved to be biased from a
mathematical statistical point of view, but the bias is usually not
greater than 10%. It has been shown by practical examples that the
signal-to-noise ratio affects the quality of the analytical results and
it is easy to estimate its value from practical data.