Amperometric method for the determination of nitrate in water

An amperometric method for the determination of nitrate in water has been developed. A small addition of acid copper sulfate is made to the sample and a potential pulse sequence is used to measure the current for the reduction of nitrate at an in situ, freshly plated copper surface. The procedure works well for the nitrate concentration range 0.1-1 mM, important for water intended for human consumption; there appear to be no serious interferences, for example chloride ion at the maximum permitted level does not interfere.