A novel threshold criterion based on the degree of peak overlap is pro
posed. It can be used for the evaluation of the degree of separation f
or simple or complex mixtures. The criterion considers quality of sepa
ration for relevant peaks only. Non-symmetrical peak shapes, different
peak-height ratios and the influence of other peaks on the separation
are also considered. The proposed criterion was tested on overlapped
peaks of complex chromatograms obtained by capillary gas chromatograph
y.