-transparent.png){kind=logo}
When nitrogen dioxide (NO2) samplers were exposed at several reduced pressures, it was found that the sampling rate was correspondingly decreased; that finding did not agree with accepted diffusional theory. When the experiments were repeated using water vapor as the gas and molecular sieve as the sorbent, the observed sampling rates were in very good agreement with diffusional theory. These findings demonstrated that the pressure effect was not common to all diffusional samplers and suggested that there might be an alternate explanation for the results with NO2-triethanolamine (TEA). The best possibility appeared to be the dehydration of TEA that takes place at reduced pressures. That this is a very significant factor was demonstrated by simultaneous exposure to identical concentrations of NO2 at 1 atm and 50% or 0% relative humidity. In dry air the sampling rate was equivalent to that found previously at about 1/10 atm. The earlier results can be satisfactorily explained as indirect rather than direct effects of reduced pressure.
E D Palmes, and
E R Johnson
January 1986,
Sozial- und Praventivmedizin,
E D Palmes, and
E R Johnson
October 1976,
American Industrial Hygiene Association journal,
E D Palmes, and
E R Johnson
December 2023,
MethodsX,
E D Palmes, and
E R Johnson
December 2012,
Analytical chemistry,
E D Palmes, and
E R Johnson
May 1998,
British journal of anaesthesia,
E D Palmes, and
E R Johnson
January 1998,
Medycyna pracy,
E D Palmes, and
E R Johnson
August 1999,
Journal of environmental monitoring : JEM,
E D Palmes, and
E R Johnson
November 1991,
Journal of the Air & Waste Management Association,
E D Palmes, and
E R Johnson
November 1977,
International archives of occupational and environmental health,
E D Palmes, and
E R Johnson
June 2021,
Scientific reports,
