Cavity ring-down spectroscopy with an automated control feedback system for investigating nitrate radical surface chemistry reactions

Details

• Personal Author:
  Flemmer MM ; Ham JE
• Description:
  Nitrate radical (NO3*) surface chemistry of indoor environments has not been well studied due to the difficulty in generating and maintaining NO3* at low concentrations for long term exposures. This article presents the Surface Chemistry Reactant Air Delivery and Experiment System (SCRADES), a novel feedback controlled system developed to deliver nitrate radicals at specified concentrations (50-500 ppt, +/-30 ppt) and flow rates (500-2000 ml min-1) to a variety of indoor surfaces to initiate reaction chemistry for periods of up to 72 h. The system uses a cavity ring-down spectrometer (CRDS), with a detection limit of 1.7 ppt, to measure the concentration of NO3* supplied to a 24 1 experiment chamber. Nitrate radicals are introduced via thermal decomposition of N2O5 and diluted with clean dry air until the desired concentration is achieved. Additionally, this article addresses details concerning NO3* loss through the system, consistency of the NO3* concentration delivered, and stability of the CRDS cavity over long exposure durations (72 h). [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Air Pollution, Indoor Aldehydes Butanones Chemistry Chemistry, Analytic Dicarboxylic Acids Environmental Health Formaldehyde Nitrates Occupational Health Safety

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• Keywords:
  Air-contamination Analytical-chemistry Analytical-processes Carboxylic-acids Dicarboxylic-acids Indoor-air-pollution Indoor-environmental-quality Ketones Organic-compounds
• ISSN:
  0034-6748
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  83
• Issue:
  8
• NIOSHTIC Number:
  nn:20041478
• Citation:
  Rev Sci Instrum 2012 Aug; 83(8):085103
• Contact Point Address:
  Jason E. Ham, Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, West Virginia 26505
• Email:
  bvo2@cdc.gov
• Federal Fiscal Year:
  2012
• NORA Priority Area:
  Healthcare and Social Assistance ; Services
• Peer Reviewed:
  True
• Source Full Name:
  Review of Scientific Instruments
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:6a4aa258256c239ca96f7bca60c09829c8b1f9d7e5f6ab2f58a712672c4a0cf629d074f2555aee7568b95cdb81b3906dbc0aa699b81fdb5f1406ab2cbcf6a15e
• Download URL:
  https://stacks.cdc.gov/view/cdc/194040/cdc_194040_DS1.pdf
• File Type:
  [PDF - 747.04 KB ]