Abstract
A numerically calculated method was used to study the influence of radial heterogeneity upon columns of different lengths. In this study, we assumed the fourth-order polynomial distribution function of mobile phase flow velocity and the local efficiency. The results relating to column efficiencies and tailing factors show that long and high efficiency columns are influenced by radial heterogeneity more than the shorter and low efficiency columns are influenced. Radial heterogeneity has various effects on columns of different lengths. The results indicate that an extreme high efficiency column has a threshold of length. When the length exceeds the threshold, increasing length will not result in a significant increase in the column plate numbers. The influence of radial heterogeneity upon mobile phase flow velocity and local column efficiency also varies. The radial distribution of local efficiency can enhance the effects of the mobile phase flow velocity radial distribution.