Effects of process parameters on the efficiency of chromatographic separations using a cuboid packed-bed device

In recent papers we have proposed cuboid packed-bed devices as viable alternatives to preparative columns with low bed-height to diameter ratios that are typically used for biopharmaceutical purification processes. In this case study, we systematically examined operating parameters such as mobile phase flow rate, sample injection volume and feed protein concentration on the characteristics of flow-through and bound-and-eluted protein peaks. The current study was carried out using strong anion exchange media packed in a cuboid packed-bed device and its equivalent column, i.e. with identical volume and bed-height. Our experimental results showed that the cuboid packed-bed device outperformed its equivalent column at all conditions examined. However, the improvement in performance in flow-through experiments was more significant at lower flow rates, and when smaller sample volumes (i.e. less than 20% of bed volume) were injected. Also, the performance of the cuboid packed-bed was significantly better when a concentrated protein sample was injected using a small volume loop. In bind-and-elute experiments, the flow rate had a very significant impact on the performance of the cuboid packed-bed device, with better results being obtained at the lower flow rates examined. By choosing appropriate experimental conditions, significantly sharper peaks and thereby efficient separations could be achieved using the cuboid packed-bed device than with its equivalent column.