Patent ID: 6852212

Claim:
A method for estimating the concentration of a reduced or oxidized form of a redox species in a liquid comprising the steps of: (1) contacting an area of a first electrode with a sample of predetermined volume of the liquid, (2) bringing a second electrode into a closely spaced relationship with the first electrode, thereby contacting the sample with an area of the second electrode spaced apart from the first, wherein step (2) is conducted after step (1), (3) applying a potential between the electrodes while the electrodes are sufficiently closely spaced that reaction products formed at each electrode diffuse to the other electrode while the potential is applied, (4) measuring or estimating a value indicative of the change in current as a function of time and a value indicative of the steady state current, and (5) determining from said value, said current as a function of time, and said steady state current the concentration of reduced or oxidized form of the species in the liquid sample wherein at least one of the electrodes is in the form of a continuous strip.