Equation for evolution of temporal width of a solute band migrating in chromatographic column

Abstract

An alternative differential equation to model the development of the temporal width of a solute band during its migration in a chromatographic column is developed. This model uses the solute residency, the inverse of the solute velocity, as parameter, which has the advantage to be an always finite quantity even at the column outlet in GC–MS where carrier gas velocity approaches infinity. The new differential equation is derived from a known equation describing the evolution of the spatial variance of migrating band. Supplemental material illustrating solutions of the newly developed equation in several special cases is provided.