Organic Acids and Nitrogen Dioxide

Nitrogen dioxide and organic acids can be measured using simple diffusive samplers that are easy to deploy for indoor air quality, workplace exposure, or area-monitoring studies. These samplers do not require pumps, batteries, or specialized field equipment. They can be clipped near the breathing zone for personal exposure monitoring or placed in a strategic indoor location to evaluate area concentrations. This product is especially useful for measuring nitrogen dioxide in indoor air. Nitrogen dioxide is an important indoor air pollutant that can be produced by combustion sources such as gas stoves, furnaces, boilers, fireplaces, vehicle exhaust intrusion, and other fuel-burning equipment. Measuring nitrogen dioxide can help identify whether combustion-related pollutants are accumulating indoors and whether ventilation or source-control improvements are needed. Please see our nitrogen dioxide in indoor air page for further information. Organic acids can also be measured with this type of sampler. Exposure time can range from 15 minutes to 7 days, depending on the expected concentration and the purpose of the measurement. Care should be taken not to saturate the sensor. The maximum mass of formic acid that can be absorbed is reported to be 800 microg, so 50 ppm formic acid for 8 hours should be considered the upper practical limit for this sampler. Similarly, the maximum mass of acetic acid that can be absorbed is 500 microg, so 25 ppm acetic acid is the maximum concentration you should plan to sample. Longer sampling times, up to 7 days, are intended for indoor air quality measurements where organic acids are present at ppb levels rather than being directly used in the space. These low-level organic acids may be generated through natural indoor processes, such as oxidation of formaldehyde or other volatile organic compounds. The price includes the vapor sampler, return shipping, analysis, and final report. Chemical Detected CAS number Single Chemical or Multiplex SKC Diffusive Reference Method Reporting Limit (MRL) 24 h PPM Reporting Limit (MRL) 8 h PPM Reporting Limit (MRL) 15 min PPM Acetic Acid 64-19-7 Multiplex TEA UME-200 Cigic method* 0.045 0.125 4 Formic Acid 64-18-6 Multiplex TEA UME-200 Cigic method* 0.045 0.125 4 Nitrogen Dioxide 10102-44-0 Multiplex TEA UME-200 OSHA ID-182 0.0004 0.0012 0.038 *Method published by Irena Cigic, University of Ljubljana  https://doi.org/10.1186/s40494-021-00495-3