Chromatographic motion of substances involved in sequential first-order reactions

Kinetics of sequential first-order reactions occurring in a chromatographic medium is developed. A model for motion of substances of a chain 1 -> 2 -> 3 -> in an infinite chromatographic column is worked out, and a mathematical procedure and graphical method for obtaining the substance concentration as a function of reaction time and position in the column is proposed. Influence of different factors of chromatographic separation on formation of substance concentration profile is considered. Practical implementation of developed approach is demonstrated by the example of radioactive chain Ac-225 -> Fr-221 -> Bi-213 -> used for modelling a radionuclidic Ac-225/Bi-213 generator producing Bi-213 via continuous separation and decay of intermediate Fr-221.