A passive sampler for simultaneous determination of formaldehyde and nitrogen dioxide in indoor air

The author demonstrates a diffusion passive collector for simultaneous determination of HCHO and NO2 of indoor air. The passive collector consists of a bottom-equipped glass tube, a shaped insertion of refined-steel wire netting (impregnated by triethanolamine) and a polyethylene cap sealing the opening. With an exposition period of 1 to 6 days, the pollutants HCHO and NO2 can be determined within a range of 10 to 400 micrograms/m3. After cleaning the collectors by chromium sulphuric acid, they can be used for any number you like.