The amount of information conveyed by a chromatogram has been determined as a sum from each datum in a digital record. The information was calculated from the disagreement of a datum value with its predicted value. Predictions for each datum were based on its relationship to a threshold, on previous data, and on Gaussian behavior. The resulting separation number (SN) was calculated for both simulated and real data so as to determine the effect of different variables including sampling rate and noise level.