ABSTRACT
This chapter briefly discusses the application, chemical properties and physical properties of nitrogen dioxide. It presents detailed information on the air analysis of nitrogen dioxide. Nitrogen dioxide occurs in automobile exhaust and cigarette smoke. It is produced by the reaction of nitric acid with metals, decomposition of nitrates, or during fire. It reacts with water to form nitric acid and nitrogen oxide, and alkalies to form nitrates and nitrites. Nitrogen dioxide is reddish-brown fuming liquid or gas with sharp pungent odor. The air analysis of nitrogen dioxide may be performed by using passive indicator tubes, various passive samplers, and electrochemical instruments. During the air analysis, air is drawn through Palmes tube with three triethanolamine (TEA)-treated screens. The analyte converted into nitrite ion is treated with an aqueous solution of a reagent mixture containing sulfanilamide, H3PO4, and N-1-naphthyl-ethylenediamine dihydrochloride. Concentration of nitrogen dioxide may be measured directly by passive colorimetric dosimeter tubes.
