Author(s)

F. De Santis, P. Di Filippo & I. Allegrini

Abstract

A diffusion denuder for ambient nitrogen dioxide, based on quantitative collection on an alkaline active carbon surface, has been developed. Nitrogen dioxide yields nitrite anion which is extracted after sampling with water and analyzed by ion chromatography It was found that the use of an alkali makes negligible the reduction ofNO] to NO, which occurs in working conditions on a simple surface of active carbon Laboratory and field tests concerning sorption efficiency, capacity and effect of humidity have been carried out The pre- exponential and esponent for the first term of the Gormley equation applied to annular geometry, were estimated The detection limit for 24 h sampling is better than 0.05 ppb Nitrogen oxide, ozone and PAN do not interfere in the determina

Keywords