Studies Of Theophylline Imprinted Phenolic Resin Sorbent

By the technology of inverse suspension polymerization, theophylline template phenolic resin sorbent(TTPS) and non-template phenolic resin sorbent(NTPS) have been synthesized.TTPS and NTPS were characterized by infrared spectroscopy, surface area analyzer,SEM, and so on. The result shows that there are more porous structures in TTPS microsphere than in NTPS microsphere.The theophylline adsorption on TTPS and NTPS has been studied. The experimental results showed that the adsorption data fitted the Langmuir model, which implied the monomolecular layer sorption in these systems. Theophylline adsorption data matched Freundilich equation within the lower concentration, which meant the adsorption was preferential.By Scatchard analysis, it was found that TTPS showed specific binding sites.The dissociation constants and the maximum binding capacity were calculated to be K_d1=0.129mmol/L, Q_max1=138μmol/g for high affinity binding sites and K_d2=0.433mmol/L, Q_max2=184μmol/g for lower affinity binding sites, respectively. Moreover, it was found that the sorption rate data of theophylline adequately fitted a semi-empirical rate equationn in initial period. It confirmed the particle-diffusion control mechanism of the sorption process.Adsorption of TTPS and NTPS in constant temperature has been studied.The result shows that both TTPS resin and NTPS resin accorded with Langmuir and Freundlich models.In addition, the adsorption kinetics of the TTPS resin also suggested the accordance with Boyd film diffusion equation. It indicated that particle diffusion controlled the rate of adsorption.Thermodynamic changes in the process of adsorption of theophylline are studied,the result show that: the enphalpy change of adsorption are -21.21kJ/mol, indicate that the process of adsorption accompanied with exothermic. The force between template molecules and monomers is hydrogen bonding force.When 2.00mmol/L solution of theophylline at the rate of 3BV/h flowed through TTPS columns, breakthrough point was 24th bed volume under dynamic condition. It was clear that 1mol/L hydrochloric acid at the rate of desorption 1.5BV/h for removing 97.2% all the theophylline adsorbed on TTPS were 4 bed volumes. The result showed that TTPS possessed excellent desorption performance.