Liquid Selective Electrodes for Dextromethorphan Hydrobromide Based on a Molecularly Imprinted Polymer in PVC Matrix Membrane

摘要

Liquid and graphite coated electrodes of polymers imprinted with dextromethorphan hydrobromide(DM) were constructed using precipitation polymerization. The molecularly imprinted (MIP) andnonimprinted (NIP) polymers were synthesized using DM as a template, acrylic acid (AA) and 2-vinylpyridine (VPY) as monomers, ethylene dimethacrylate (EDMA) as a cross-linker and benzoyl peroxide(BPO) as an initiator. The molecularly imprinted membranes and the non-imprinted membranes wereprepared using dioctyl phthalate (DOP) and bis (2-ethylhexyl) sebacate (BEHS) as plasticizers in PVCmatrix. The slopes and detection limits of the liquid electrodes ranged from 55.9 58.3 mV/decade-6 -5and 3.0 x 10 6.0 x 10 M, respectively and their response time was about 1 minute. The Liquidelectrodes were filled with 0.01 M DM solution and their response was stable in a pH range from 2.0to 9.0 and with good selectivity for DM over several species. Graphite electrodes coated with MIPmembrane of AA and DOP and AA and BEHS were prepared for DM determination. Graphiteelectrodes coated with MIP membrane of AA and DOP showed a near Nernstian response with slope-7 -2of 52.4 mV/decade and a linear response for a concentration range of 5.0x 10 to 1.0 x 10 M and aresponse time of around 1 minute. The most effective electrodes were used to determine theconcentration of DM in cough syrups.