Pulsed current anion selective electrodes

A method of selectively measuring a concentration of an anion in a liquid sample, the method comprising:

• a sample exposure step of exposing an ion-selective electrode (ISE) to the liquid sample, the ion-selective electrode comprising:
• a working electrode;
• a transduction layer disposed on the working electrode;
• and,
• an ion-selective membrane (ISM) disposed on the transduction layer, the ISM having a thickness that is less than 100 μm,
• such that a sample-ISM interface forms between the liquid sample and the ISM;
• an equilibration step in which an equilibrium phase boundary potential is formed at the sample-ISM interface;
• a charging step of applying an electrical current pulse to reversibly oxidize the transduction layer, during which charged phase boundary potential at the sample-ISM interface is measured and recorded;
• a phase boundary change calculation step comprising subtracting the equilibrium phase boundary potential from the charged phase boundary potential to calculate a phase boundary potential change Δφ;
• and
• a concentration calculation step of calculating the concentration of the anion in the liquid sample from the phase boundary potential change Δφ.

A system for selectively measuring the concentration of an anion in a liquid solution, the system comprising:

• an ion-selective electrode comprising:
• a working electrode;
• a transduction layer disposed on the working electrode;
• and,
• an ion-selective membrane (ISM) disposed on the transduction layer, the ISM having a thickness less than 100 μm;
• an analytical instrument operably connected to the ion-selective electrode;
• a reference electrode operably connected to the analytical instrument;
• and
• a counter electrode operably connected to the analytical instrument.