Abstract
Evidence of a new type of secondary poll utants in photochemical smog, dinitrates, has been presented. Propylene glycol 1,2‐dinitrate (PGDN) was identified as a product in the photooxidation of a propylene‐nitrogen oxides‐air system using an evacuable and bakable smog chamber. The concentrations of the products were measured quantitatively in‐situ by a long‐path Fourier transform infrared spectrometer. The yield of PGDN was about 0.10 ppm when the mixture of 3.0 ppm of C3H6 and about 1.5 ppm of NOX was irradiated in air. The yield of PGDN was nearly the same for both the dry and humidified air system.