Concentration Signal in the Case of Mixtures

Usually mixtures are regarded as separated, if the individual components in the chromatogram are obviously separated. Theoreticians have worked out separation factors, etc. [5]. 

If the signals of the individual components are not separated completely, then we must add to the signal also the contributions of substances that are super-positioned. This is valid for each individual component that should be resolved. In general, a chromatogram is obtained by summing the individual signals of concentration. 

Here for each component a retention time was associated with an index i. 

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