Functionalized Adsorbents for the Purification of Cephalosporin C and Deacetylcephalosporin C

In the present work, the adsorption of cephalosporin C and deacetylcephalosporin C on six different adsorbents has been studied. Two of the adsorbents were commercial Amberlite XAD-2 and Amberlite XAD-4, and the other four were their corresponding brominated and bromoethylated derived resins, respectively. The research was carried out by means of pulse experiments in a high-performance liquid chromatography (HPLC) system, and the corresponding chromatographic responses were analyzed using the moment theory. The results showed that the chemically modified XAD-2 resins enhanced the adsorption constant for cephalosporin C. Specially, brominated XAD-2 resin showed an increase in KA of ~3× with respect to the commercial adsorbent at 15 °C. In addition to the equilibrium and thermodynamic properties of the adsorption process, the effective pore diffusion coefficient, Dp, was also calculated. In all experimental conditions, the values of Dp were always larger for the modified resins, showing a consequent decrease in the internal mass transfer resistance of both cephalosporin C and deacetylcephalosporin C.