抄録
An improved method for the determination of nitrogen oxides in stack gases has been developed, the principle of which is based on the measurement of nitrate ion, produced by the oxidative absorption of nitrogen oxides with ozone and hydrogen peroxide, by nitrate ion electrode. The oxidizing agent used in the conventional method such as phenol disulfonic acid (PDS) method was molecular oxygen, and it required more than 16 hr for the complete oxidation of nitrogen monoxide. The use of ozone instead of oxygen resulted in a considerable reduction in time, because oxidation of nitrogen monoxide was completed within several minutes. The use of nitrate electrode was advantageous in simple procedure and reproducible results. Furthermore, the proposed method was not affected in the presence of 7000 ppm of SO2, 1800 ppm of HCl, and 5000 ppm of NH8. The analytical results obtained by both the proposed method and the PDS method showed agreement within 5%.
