[Simulation of gas chromatographic peak motion process]

Solute motion process under different temperature, pressure and/or flow program conditions is simulated with the aid of numerical calculation of the differential equation. It is demonstrated that there exist some differences between the normalized average linear velocity and the normalized local linear velocity. As time develops, they intercept, and may not reach the column end at the same time, thus may result in errors in retention time simulation. In constant pressure process, where the compressibility factor (j) does not change, simulation results in a model index of 1, and no model difference can be found when the integrate equation is used. In pressure varying process, where j changes by time, simulation results in an model index which deviates to 1, and positive (for a j decrease process) or negative (for a j increase process) error can be found when the integrate equation is used. The numerical solution of the differential equation is singular under given programs, which corresponds to a specific space line in z, t, u coordinates.