Abstrakt
Cyclic voltammetry is used to investigate the transfer of heparin polyion across the interface between water and the ionic liquid (IL) membrane composed of tridodecylmethylammonium cation (TDMA +) and tetrakis[3,5-bis(trifluoromethyl) phenyl]borate anion (TFPB -). Study reveals a tunable effect of the semihydrophobic tetraalkylammonium cations (TAA +) present at trace concentrations in the aqueous solution containing heparin.
Theoretical considerations based on the mixed-potential concept and experimental evidence suggest that the TAA + cations promote the extraction of heparin into the IL phase, from which heparin can be stripped off by applied potential providing a well-separated current signal. A new method for the amperometric detection of heparin is proposed.