Nitron Thin Film Method for Detection of Submicron Nitrate Particles and its Application to Atmospheric Aerosols

摘要

A method for the detection of individual submicron nitrate particles has been developed. It is based on the reaction of the nitrate ion with a nitron thin film. A nitron thin film is prepared by a vacuum deposition of nitron and, from the measurements of infrared spectra, it is found that a nitron thin film is not modified in the process of a vacuum deposition. The reaction of nitrate in individual particles with a nitron thin film proceeds . under the octanol saturated atmosphere. Under this reaction condition, the presence of nitrate in individual particles is indicated by the appearance of a bundle of needle-like crystals and the reaction is reproducible. It is also found that under this reaction condition the sulfate and chloride ions contained in atmospheric aerosols do not interfer, The method is specific for nitrate and particles containing nitrate of more than 10-14gr can be detected. An example of the application of the method to atmospheric aerosols is shown.