Use of electrode system for measuring hydrogen peroxide concentration

• US 5,518,591 A
• Filed: 08/18/1994
• Issued: 05/21/1996
• Est. Priority Date: 08/20/1993
• Status: Expired due to Fees

• Current Assignee: Conrex Automation OY
• Original Assignee: Conrex Automation OY
• Inventors: Savisalo, Hannu, Pulliainen, Martti, Laurila, Timo
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/292,373
• Time in Patent Office: 642 Days
• Field of Search: 204/412, 204/400, 204/153.1, 204/292, 204/403, 204/153.12, 204/153.11, 436/150
• US Class Current: 205/782
• CPC Class Codes: G01N 27/4045 for gases other than oxygen

Abstract

An electrode system and method, including a measurement electrode, a reference electrode and a counterelectrode, for measuring hydrogen peroxide concentration in a solution. For the measurement electrode, an electrode made from titanium, zirconium, tantalum or niobium is used.

Claims

1. Method for measuring the concentration of hydrogen peroxide in a solution, comprising the steps of:

coupling a measurement electrode formed from a material selected from the group consisting of titanium, zirconium, tantalum and niobium, a reference electrode and a counterelectrode with the solution containing hydrogen peroxide,

maintaining a voltage between said measurement electrode and said reference electrode,

measuring the rate of corrosion of said measurement electrode while hydrogen peroxide reacts with the material of said measurement electrode and causes electrochemical corrosion thereof, and

determining the concentration of hydrogen peroxide from the measured corrosion rate.

2. The method of claim 1, further comprising the steps of

measuring a difference between potential between said measurement electrode and the solution and potential between said reference electrode and the solution, and

determining the concentration of hydrogen peroxide from the measured potential difference which correlates to the corrosion rate of said measurement electrode.

3. The method of claim 1, further comprising the steps of:

coupling a potentiometer to said measurement electrode, said reference electrode and said counterelectrode, and

measuring the electrochemical potential of said measurement electrode which correlates to the concentration of hydrogen peroxide in the solution by means of said potentiometer.

4. The method of claim 1, wherein the voltage between said measurement electrode and said reference electrode is maintained substantially constant whereby the hydrogen peroxide reacts with the material of said measurement electrode and causes electrochemical corrosion thereof, further comprising the step of

determining the concentration of hydrogen peroxide from a measured current density required to maintain the substantially constant voltage which correlates to the corrosion rate of said measurement electrode.

5. The method of claim 4, wherein the step of determining the concentration of hydrogen peroxide from the measured current density comprising the step of:

varying the voltage within a range of voltages in each of a plurality of solutions, each solution having a known hydrogen peroxide concentration which differs from the hydrogen peroxide concentration of the other solutions to thereby obtain polarization curves of said measurement electrode as a function of hydrogen peroxide concentration.

6. The method of claim 5, further comprising the step of determining a maximum current value from said polarization curves which correlates to the concentration of hydrogen peroxide.

7. The method of claim 5, further comprising the step of charting current density as a function of hydrogen peroxide concentration such that for a known, measured current density of the solution, the hydrogen peroxide concentration can be obtained.