title: Development of a cobinamide-based end-of-service-life indicator for detection of hydrogen cyanide gas.
abstract: We describe an inexpensive paper-based sensor for rapid detection of low concentrations (ppm) of hydrogen cyanide gas. A piece of filter paper pre-spotted with a dilute monocyanocobinamide [CN(H2O)Cbi] solution was placed on the end of a bifurcated optical fiber and the reflectance spectrum of the CN(H2O)Cbi was monitored during exposure to 1.0-10.0 ppm hydrogen cyanide gas. Formation of dicyanocobinamide yielded a peak at 583 nm with a simultaneous decrease in reflectance from 450-500 nm. Spectral changes were monitored as a function of time at several relative humidity values: 25, 50, and 85% relative humidity. With either cellulose or glass fiber papers, spectral changes occurred within 10 s of exposure to 5.0 ppm hydrogen cyanide gas (NIOSH recommended short-term exposure limit). We conclude that this sensor could provide a real-time end-of-service-life alert to a respirator user.
authors.affiliation: Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health/National Personal Protective Technology Laboratory (CDC/NIOSH/NPPTL), 1095 Willowdale Road, Morgantown, WV 26505, USA.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Greenawald
authors.affiliation: 113 Snee Drive, Jefferson Hills, PA 15025, USA.
authors.forename: Jay L
authors.initials: JL
authors.lastname: Snyder
authors.affiliation: Department of Chemistry and Biochemistry, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Fry
authors.affiliation: Department of Chemistry and Biochemistry, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sailor
authors.affiliation: Department of Medicine, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: Gerry R
authors.initials: GR
authors.lastname: Boss
authors.affiliation: C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University, Morgantown, WV 26506, USA.
authors.forename: Harry O
authors.initials: HO
authors.lastname: Finklea
authors.affiliation: C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University, Morgantown, WV 26506, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Bell
keywords: Cobinamide; Diffuse reflectance; End-of-service-life indicator; Hydrogen cyanide; Optical sensor; Paper sensor