Time difference scanning gel chromatography: computer simulations

The time difference profile method of gel scanning chromatography developed by Brumbaugh, Saffen and Chun (Biophysical Chemistry, 1979) has been examined by computer simulation. The method is found to produce values for centroid movements that mimic those of the system being examined but are not quantitatively correct. In all cases the time differential "centroid" is larger than that of the concentration derivative (true) centroid and move at a rate slightly faster than the true centroids. This faster rate slowly decreases towards the true rate but does not approach it within reasonable times. This distorted movement reflects the distorted emphasis given to the larger species in the time differential method. The time difference method has been shown to give an adequate measure of the axial dispersion coefficient, L, for single species systems.