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Published on: December 20, 2016
Nitrous acid interference with passive NO2 measurement methods and the impact on indoor NO2 data
C W Spicer1, I H Billick, Y Yanagisawa
1Atmospheric Science and Applied Technology Department, Battelle, 505 King Avenue, Colombus, Ohio 43201, USA. spicerc@battelle.org
Indoor Air
|August 28, 2001
Summary
Nitrous acid (HONO) interferes with indoor nitrogen dioxide (NO2) measurements. This study found HONO quantitatively affects three of four tested passive NO2 sampling devices, impacting indoor air quality assessments.
Area of Science:
- Environmental Science
- Analytical Chemistry
- Indoor Air Quality
Background:
- Nitrous acid (HONO) is increasingly recognized as a significant indoor air pollutant.
- HONO is formed indoors via nitrogen dioxide (NO2) reactions with surfaces and direct emission from combustion.
- Previous studies identified HONO interference with continuous NO2 monitors.
Purpose of the Study:
- To evaluate the interference of HONO on nitrogen dioxide (NO2) measurements using passive sampling devices.
- To assess the accuracy and precision of passive samplers for indoor NO2 monitoring in the presence of HONO.
Main Methods:
- Evaluation of four different types of passive NO2 sampling devices.
- Controlled experiments to quantify the effect of known HONO concentrations on NO2 measurements.
- Comparison of results from passive samplers against established NO2 measurement standards.
Main Results:
- Nitrous acid (HONO) was found to interfere quantitatively with three out of the four passive NO2 samplers tested.
- The interference level varied among the different passive sampling devices.
- This interference can lead to inaccurate indoor NO2 concentration readings.
Conclusions:
- Passive NO2 samplers commonly used for indoor air quality monitoring are susceptible to interference from HONO.
- The quantitative interference necessitates careful consideration when interpreting indoor NO2 data obtained from these devices.
- Further development or selection of HONO-resistant passive samplers is recommended for accurate indoor NO2 assessment.
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