1997 Volume 13 Issue 6 Pages 975-979
The potential response to ethanol was examined by a flow-through ion sensor using a plasticized poly(vinyl chloride) membrane doped with several amphiphilic ions. When an amphiphilic cation was used, a negative potential slope to ethanol was observed. When an amphiphilic anion was used, however, a positive potential slope was observed. These potential slopes were affected by the hydrophobicity and the shape of the amphiphilic ions. The results of these potential slopes supported the mechanism previously proposed for the potential response to anionic polyelectrolyte, that is, the change of phase-transfer force of the amphiphilic ion from the membrane to the sample solution dominated the potential response. The present ISE method was applied to the determination of ethanol in several liquors. The determination values agreed well with those obtained by a gas chromatographic method.