Spectrophotometric Determination of Total Oxides of Nitrogen

摘要

An accurate and rapid method is proposed for the determination of total oxides of nitrogen in gases from initiators and other explosive devices. Total oxides of nitrogen include nitric oxide, nitrogen dioxide, nitrogen trioxide, nitrogen tetroxide and nitrogen pentoxide. It is frequently customary to determine the total of these oxides because of the similarity in their toxicity, mode of formation, and the ease with which they are converted to each other in equilibrium reactions. In the proposed method the oxides are treated with air and are absorbed into sulfuric acid (10 to 3). Ferrous sulfate reagent is then added and the pink color is measured. It is not necessary that the air oxidize nitric oxide completely. It is shown that nitrate and nitrite give the same color with the ferrous sulfate reagent. The method was checked by a technique using a modified Hamilton syringe, together with a special gas bulb and laboratory cylinders of nitric oxide and nitrogen dioxide. (Author)