The mass balance for a zero length column (ZLC) system leads to a very simple check which can be used to ensure internal consistency of the experimental curves. This is based on reporting experiments run at different flow rates on a c/c(0) vs. Ft plot, where F is the volumetric flow rate. The proposed method is applied to two different sets of results from the literature and can be used to identify that in one case the data are inconsistent. The results lead to an important recommendation: any future contribution reporting ZLC curves should include the c/c(0) vs. Ft plot which can confirm the internal consistency of the results and indicate if the experiments are carried out under equilibrium or kinetic control.