ISOTROPIC TRACING AND HIGH RESOLUTION INFRARED FT SPECTROSCOPY IN LABORATORY STUDIES OF ATMOSPHERIC CHEMISTRY
Investigations on aspects of nighttime tropospheric chemistry centred on the reactions of NO3 and the product in equilibrium N2O5, have been performed in the laboratory using a large (450L) gas reaction chamber and IRFt spectroscopy as analytical technique. When high instrumental resolution (0.06 cm1 FWHM) is used, isotopic species of small molecules can be separately identified and quantitatively evaluated from their infrared spectra. This characteristic has been favourably utilized in the study of the reaction NO3 f5 CO. Also important is the possibility of using the formation of isotopic compounds to evaluate with high sensitivity and specificity the formation of particular species in complex chemical systems. This is the case of adding C13O18 to evaluate the OH radical concentration from the buildup of O16C13O18 formed by the reaction COf5OH; a technique applied in the study of the reaction CH2O f5 NO3. IRFTS was also used in the study of the homogeneous phase reactions N2O5 f5<&F1< H2O. Time dependent concentrations of C13H2O, C13O16, HC13OOH, O16C13O18 NO2, N2O5, HNO3 could be measured by IRFTS and the data fitted on the basis of a model involving 31 reactions using computer programs to derive a rate constant for the reaction CH2O f5 NO3. In the frame of these studies, the evaluation of absolute spectral parameters of N2O5, HNO3, HCOOH was performed; the advantages of the use of the large reaction chamber as gas cell in these measurements are discussed.
Bibliographic Reference: 6TH INTERNATIONAL CONFERENCE ON FT-SPECTROSCOPY, WIEN (AUSTRIA), AUG. 24-28, 1987 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 33542 ORA
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Record Number: 1989126001000 / Last updated on: 1988-02-01
Available languages: en