Selective adsorption of vitamin E from palm fatty acid distillate on silica-packed fixed-bed columns.

摘要

Understanding the behavior of vitamin E adsorption during chromatographic separation allows better control of the process. In this study, a pre-concentrated vitamin E fraction from palm fatty acid distillate (PFAD) was subjected to a normal phase silica-packed fixed-bed column for further purification. Effects of various operational parameters i.e. column bed height, vitamin E inlet concn., column temp. and flow rate on column performance were determined. Breakthrough curves of all systems had typical S-shaped profiles. The service time of the column increased after increasing the column bed height or reducing the inlet concn., column temp. and flow rate. Column efficiency in terms of adsorbent usage rate could be improved by decreasing the inlet concn. and flow rate. Decreasing the column temp. resulted in higher column capacity, suggesting that the adsorption of vitamin E on silica was an exothermic process. The bed depth service time (BDST) model described the adsorption process well, with coeff. of determination ranging from 0.92 to 0.99 and low residual sum of square (<0.28) and standard error (<0.35). The model provided a good explanation of the characteristic operational parameters, except for the effect of flow rate.