SUPERPOSITION OF CHROMATOGRAPHIC RETENTION PATTERNS

The retention pattern of multicomponent chromatograms is studied. When the sample being analyzed is a mixture of some structured series of compounds, the simplest models fail to characterize the interval distribution of adjacent peaks. In this study, the effect of superposition is explained, showing that even the mixture of samples that give strictly deterministic chromatograms individually turns disordered. The resultant interval distribution rapidly approaches the exponential distribution. For this reason, a second-order property (the variance-time curve) is needed to recognize the fact of superposition, The variance-time curve also allows the determination of the number of individual chromatograms, i.e., the number of families of compounds. The model was applied to two sharply different multicomponent chromatograms: that of a chamomile flower extract and a naphtha sample, proving that the former one is a true disordered sample while the latter one is the product of the superposition of structured sources.