Prediction of formic acid chromatogram in gradient elution chromatography

Optimal operation in chromatography is needed to save operation time and the solvent used in multiple chromatographic runs. To this end, many simulation studies of chromatography process have been performed. The relationship between the distribution coefficient and the ionic strength is important in gradient elution ion chromatography. Experimental runs and computer simulations were carried out under linear gradient elution conditions in order to compare the experiments and the simulation. Experiments were performed with formic acid under isocratic conditions to determine the simulation equation parameters. Computer simulation was based on three equations which related distribution with ionic strength as follows; K=αI-β, K=A+BI+CI2 and K=y0+A1 · e(-I/m1)+A2 · e(-I/m2). The effects of gradient slope on the chromatograms are discussed, and good agreement between the experimental and the simulated results is shown.