Separation of solid phase synthesis thymopentin using ion-exchange method

Nowadays, reverse phase liquid chromatography (RPLC) is the usual way to purify the peptide. But the efficiency of this method is low and the cost is high, and it is also limited to small scales. In this paper, we use the ion-exchange chromatography and discuss several factors that will influence the process of separation, such as adsorption dynamics, pH, buffers and variety of resins. The experiments show that when using SP sepharose FF resin and pH 4.4 acetic buffers, we will get good results of separation. After optimizing the experiments' conditions, we found that under pH 4.4 acetic buffer binding and salt elution, the purity of TP5 which was analyzed with high pressure liquid chromatography (HPLC) and mass spectrum (MS) could reach 98% or more in one step. This method can also satisfy the requirements of large-scale preparation.