EVIDENCE FOR ADSORBED SO2 AT THE AQUEOUS AIR INTERFACE

We present direct experimental evidence for the existence of a surface -bound state of partially hydrated SO2 on water. Surface second harmon ic generation (SHG) and static surface tension measurements are used t o examine the SO2 surface coverage as a function of its bulk aqueous c oncentration. The results indicate a Langmuir-type adsorption of SO2 a t the air-water interface. These experiments represent the first repor t of the application of surface SHG techniques to detect gas adsorptio n onto a liquid surface.