Fundamental Studies on Sampling Method of Particulate Nitrite in the Air

Abstract

Particulate nitrite (NO₂^-) was generated by introducing purified air (12.5l/min) in 1.38-13.8 mg/ml NaNO₂ aqueous solution contained in a glass spherical nebulizer, to investigate the sampling method and the chemical behavior of the NO₂^-in the air. Saltzman method was also investigated for sampling of particulate NO₂^-, comparing with filter method.
NO₂^- could be generated at any concentration and the concentration may be maintained constant for long period of time (>4 hr), and NO₂^- impregnated filter was able to be prepared dynamically.
Filter method, as well as Saltzman method, is applicable to the NO₂^-sampling at high concentration (0.1-1 mmol/m³), but in both methods, it is necessary to remove interfering substances (O₃-H₂O and NO_x), for the sampling at atmospheric concentration.