Analyte separation by OMNiMIPs imprinted with multiple templates

Changes detected in the imprinting effect by OMNiMIPs imprinted with multiple templates appear to be a function of the maximum template loading. Below the maximum template loading, the polymers imprinted with multiple compounds provide molecular recognition close to the polymers imprinted with single compounds, for each template compound tested. However, template loading past this point can result in significant lowering of the imprinting effect. For example, 1,1'-bi-2-naphthol enantiomers showed nearly a 60% loss in enantioselectivity on OMNiMIP 8 (imprinted with four templates): yet still maintained a separation factor of 3.7 allowing baseline separation of enantiomers. Similar behavior was seen for the other three template molecules, although losses in enantioselectivity were less severe. The multi-analyte imprinted OMNiMIP 8 was shown to be capable of separating a template molecule individually from a mixture, including enantiomers, but not all four concurrently. With respect to physical properties of the different OMNiMIPs, gradual trends in porosity and surface area correlated to the concentration of the templates, independent of their molecular structure. (C) 2009 Elsevier B.V. All rights reserved.