Design of a cell for measuring the electrical potential oscillation acrossan octanol liquid membrane

A cell was designed for measuring the electrical potential oscillation acro ss an octanol liquid membrane with a surfactant. The cell was made with an inverted U-shape so that two aqueous solutions can be poured into each side of the cell and an octanol solution can be layered on the top of the aqueo us solutions. A pair of reference electrodes, made of silver/silver chlorid e, were connected to the two aqueous solutions by a pair of salt bridges on each arm of the cell. The shape, size, and material of the cell affected t he reproducibility of the potential oscillation pattern concerning the ampl itude, oscillatory period and induction period. A square section (10.0 x 10 .0 mm) of each arm of the cell was recommended for good reproducibility of the oscillation pattern. The cell material affected the shape of the oil/wa ter interface where a potential oscillation occurs. Poly(chlorotrifluoroeth ylene) gave reproducible oscillations better than those of quartz glass or polystyrene from the view point of hydrophobicity and solvent resistance. P oly(chlorotrifluoroethylene) was easier to process than Teflon.