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Updated: Jul 24, 2026

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers
Published on: March 21, 2016
Passive sampler for measurements of atmospheric nitric acid vapor (HNO3) concentrations
A Bytnerowicz1, P E Padgett, M J Arbaugh
1USDA Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, California 92507, USA. abytnerowicz@fs.fed.us
Abstract:
Nitric acid (HNO3) vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3 concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

