| abstract |
(57) [Summary] (with correction) [PROBLEMS] To provide a gas analysis method and apparatus capable of simultaneously detecting nitrogen oxide (NO x ) and ammonia (NH 3 ) in a gas to be measured in real time. SOLUTION: By bringing a gas to be measured containing nitrogen oxide and ammonia into contact with an NH 3 strong oxidation catalyst, ammonia in the gas to be measured is oxidized and converted into nitrogen oxide; A first nitric oxide detection step of detecting the converted nitrogen oxide and the total amount of nitric oxide present in the gas to be measured, and contacting the gas to be measured with an NH 3 weak oxidation catalyst, A second nitric oxide detection step of oxidizing a part of the ammonia in the gas to be measured to convert it into nitrogen oxide, and detecting the total amount of the nitrogen oxide thus converted and the nitrogen oxide in the gas to be measured; Calculating the amount of nitric oxide and / or the amount of ammonia in the gas to be measured from the two detected values obtained in the first and second nitric oxide detecting steps. |