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Selective optical detection of aromatic vapors


, : Selective optical detection of aromatic vapors. Applied Optics 41(4): 601-608

A sensitive layer system of amorphous Teflon AF on silver has been coated on a glass substrate. With a monochromatic light source the reflectivity of the layer system as a function of the angle of incidence exhibits the surface-plasmon resonance as well as a set of leaky-mode resonances. These optical resonance phenomena are sensitive to small refractive-index changes that may be induced by diffusion of particles into the Teflon AF layer. On the basis of this effect, the aromatic vapors benzene; toluene; and o-, p-, and m-xylene have been investigated with different vapor concentrations. By selection of a distinct angle at a particular resonance, dynamic measurements can be performed. Assuming a diffusion process in accordance with Fick's law, the diffusion profile can be calculated as a function of time. As described by the Lorentz-Lorenz relation a refractive-index profile is induced that consequently interacts with the electromagnetic fields of the optical modes. With the function of the diffusion-induced refractive-index profile the shift of the resonance lines can be calculated from the measured reflectivity change as a function of time. The characteristic diffusion coefficients of the particular vapor allow for a distinction between the different types of aromate, even between the different xylenes.

US$29.90

PMID: 11993903


Other references

Kraus, E.; Femfert, U., 1976: Proteinase K from the mold Tritirachium album Limber. Specificity and mode of action. 1) The specificity of proteinase K towards amino acid and oligopeptide nitroanilide substrates is investigated. 2) The active center of the enzyme contains an extended binding region consisting of several subsites. An integral part of the S1-subsi...

Dobbins, J.; Avebury, L.; McKinney, H., 2011: The pilot AMC: the acceptance of policy evolution. Human Vaccines 7(3): 293-293

Eriyagama S.C.; Collins L.B.; Hocking R.M., 1988: Depositional framework and major lithostratigraphic variations of the Barrow Group. Pages 189-201 1988

Honda, H.; Umezawa, Y.; Kikuchi, S.; Yanaba, K.; Fukuchi, O.; Ito, T.; Nobeyama, Y.; Asahina, A.; Nakagawa, H., 2017: Switching of biologics in psoriasis: Reasons and results. Efficacy and safety profiles of biologics have been established for moderate to severe psoriasis. However, inefficacy or adverse events sometimes require changing the treatment to other biologics. Here, we examine the effectiveness of this strateg...

Klein, M.R.; Tardieu, G.; D.L.R.Va.C., 1952: Jugulocarotid anastomosis and its results in the treatment of mental retardation. La Semaine des Hopitaux 28(85): 3430-3434

Kwak, J.Hwan.; Kim, H.Jung.; Lee, K.Ho.; Kang, S.Chan.; Zee, O.Pyo., 2009: Antioxidative iridoid glycosides and phenolic compounds from Veronica peregrina. Eight iridoid glycosides and four phenolic compounds were isolated from the EtOAc soluble fraction of Veronica peregrina MeOH extract as the radical scavengers for antioxidant activity. The compounds were identified as protocatechuic acid (1), lut...

Soc Med Hop Lyon, 1967: Meeting of the societe medicale des hopitaux de lyon medical society of the lyons hospitals france november 21 1966 symposium. Semaine des Hopitaux de Paris 43(9): 605

Hong, J.C.; Nagao, R.T.; Key, J.L., 1990: Characterization of a proline-rich cell wall protein gene family of soybean. A comparative analysis. Further characterization of a proline-rich cell wall protein gene family from soybean (Glycine max (L.) Merr) has been accomplished by the isolation and sequence analysis of two additional genes, SbPRP2 and SbPRP3, which encode mRNAs of 1050 and 6...

Rodríguez-Valverde, V., 2000: Rheumatoid arthritis. Biologic treatments. Revista Clinica Espanola 200 Monog 1: 107-113

Kirkland K.; Fryer J.D., 1972: Degradation of several herbicides in a soil previously treated with 2 methyl 4 chlorophenoxy acetic acid. Weed Research 12(1): 90-95