Chemical Reactions and Molecular Aggregation in Cryogenic Whole Air Sample Matrices

摘要

This report conveys the results of an investigation concerned with the effects of chemical reactions in cryogenically condensed NOx/Ox/H2O samples, on the alteration of sample composition upon subsequent thermal desorption. These studies were undertaken to elucidate the relevant mechanisms and improve the understanding of these processes as they relate to the analysis of cryogenically-collected stratospheric whole air samples acquired in the balloon-borne sampling project of the composition task of the Stratospheric Environment Program of the Air Force Geophysics Laboratory. The results of this work indicate that interconversion of the oxides of nitrogen in condensed samples, especially in the presence of water vapor, is a significant process under certain conditions. However, additional work involving careful cryogenic deposition of very small amounts of the various species, combined with perhaps high resolution FTIR, is definitely needed in order to quantitatively assess the relative importance of these same processes in the much more highly dilute stratospheric cryogenic whole air samples.