Send to:

Choose Destination
See comment in PubMed Commons below
Rev Sci Instrum. 2012 Aug;83(8):085103. doi: 10.1063/1.4739768.

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

Author information

  • 1Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, West Virginia 26505, USA.


Nitrate radical (NO(3)(●)) surface chemistry of indoor environments has not been well studied due to the difficulty in generating and maintaining NO(3)(●) 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 NO(3)(●) supplied to a 24 l experiment chamber. Nitrate radicals are introduced via thermal decomposition of N(2)O(5) and diluted with clean dry air until the desired concentration is achieved. Additionally, this article addresses details concerning NO(3)(●) loss through the system, consistency of the NO(3)(●) concentration delivered, and stability of the CRDS cavity over long exposure durations (72 h).

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Institute of Physics Icon for PubMed Central
    Loading ...
    Write to the Help Desk