Selective separation of hydroxy polychlorinated biphenyls (HO-PCBs) by the structural recognition on the molecularly imprinted polymers: direct separation of the thyroid hormone active analogues from mixtures

We developed novel separation media for hydroxy polychlorinated biphenyls (HO-PCBs) using the molecular imprinting techniques. The results of evaluation for the molecularly imprinted polymers (MIPs) by the liquid chromatography (LC) suggested that MIPs had selective separation ability for certain HO-PCB analogues. The results of the LC evaluations and molecular modeling indicated that the molecular volumes and pK_a values of template molecules were related with the retention factor of HO-PCBs. Additionally, according to the detail evaluation toward the selective separation behaviors of MIPs, these HO-PCB analogues have low pK_a values dependent on their chemical structures. In other words, the prepared MIPs had selective recognition ability against the analogues, which have an OH group on a phenyl carbon and two chlorine atoms on the both neighboring carbons of the carbon attached with the OH group. Moreover, these analogues may have a potential for thyroid hormone activities so that we attempted to separate these analogues directly from mixtures of HO-PCBs using a prepared MIP.