A new all-season passive sampling system for monitoring NO2 in air

A new all-season passive sampling system for monitoring NO₂ in air has been developed. This passive sampling system employs the same approach as the all-season sampling system for monitoring SO₂ reported in FACT [Vol. 1(5), 1997] before, but a new collection medium (CHEMIX™) for sampling NO₂ has been developed and is used. Compared to the existing collection media used for NO₂ passive samplers, such as a triethanolamine (TEA)-coated cellulose fiber filter, CHEMIX™ is less affected by temperature and relative humidity, and has a higher sampling rate. This system has been extensively tested in the lab (temperature from −27 to 20 °C, relative humidity from 4 to 80%, and wind speed from 0.5 to 150 cm/s) and validated in the field in all climates. Comparing measurements obtained with the use of the new passive sampling system with equivalent measurements with the use of a continuous NO₂ analyzer yielded an accuracy of greater than 85%. The new NO₂ passive sampling system can be used to measure ambient NO₂ concentrations ranging from 0.1 to 50 ppb based on a 1-month exposure period. © 1999 John Wiley & Sons, Inc. Field Analyt Chem Technol 3: 338–345, 1999