Nitrate and ammonium ion-selective electrodes as sensors : Part II. Assay of nitrate ion and nitrate and nitrite reductases in stationary solutions and under flow-stream conditions

Nitrate ion-selective electrodes were successfully applied both in stationary solutions and in flow streams as new analytical techniques for the assay of nitrate reductase activity. An ammonium-selective electrode was similarly used to measure the increase in ammonium ion concentration during the enzymatic reduction of nitrate to ammonium. Preliminary studies on a true enzyme electrode for assay of nitrate ion are discussed.