Relationship between individual and competitive adsorption isotherms on molecularly imprinted polymers

Abstract

Molecularly imprinted polymers (MIP) are a new generation of selective adsorbents. In practical applications of MIPs simultaneous adsorption of at least two compounds occurs. Simultaneous (typically competitive) adsorption on MIPs has not yet been quantitatively analyzed. This paper shows that with a typical type of MIP the individual isotherms of two compounds coincide with their competitive isotherms in the logD-logq isotherm plot, where D is the distribution coefficient and q is the adsorbed concentration. Based on this observation the usual competitive isotherm, i.e., the (c1, c2) to (q1, q2) mapping can be established from the two individual isotherms. (The c-s are the respective solution phase equilibrium concentrations.) Batch separation experiments can be easily designed and the selectivity of the MIPs is also easily determined without the tedious measurement of the full competitive isotherm.