KIT COMPOSED OF SAMPLERS FOR COLLECTING AIR CONTAMINANTS/POLLUTANTS

摘要

The system consists of a series of passive samplers (APs) which sense up to 16 air contaminants or pollutants simultaneously by a diffusion process. The APs included in the kit are designed for collecting: sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), the sum of nitrogen monoxide and dioxide (NOx), ammonia (NH3), formaldehyde and acetaldehyde (HCHO and CH3CHO), organic acids: formic and acetic acids (HCOOH e CH3COOH), inorganic acids: sulfhydric, hydrochloric and nitric acids (H2S, HCl and HNO3), and volatile organic compounds: benzene, toluene, ethylbenzene and xylenes (BTEX). The kit is formed by a rectangular polypropylene box containing cylindrical samplers with an inner diameter of 21 mm and a height of 12 mm, except for the AP for BTEX, which is 14 mm high. The APs have a movable portion that holds the means for immobilising the gas of interest in a filter impregnated with a specific reagent, with a teflon membrane and a stainless steel screen on the air inlet. In the AP for BTEX, the immobilising means is composed of activated carbon. The exposure time of the kit comprising APs can vary from three to 30 days, and yields integrated average atmospheric concentrations during this time, after chemical analysis of the immobilised species.