A method using a droplet interface for passive sampling of nitrogen dioxide

The droplet method, developed by Dasgupta et. at, was applied to soluble co nstituents contained in the gas phase. They diffused to and dissolved into the liquid drop as gas stream flows across a liquid droplet. From the view point of environmental analytical chemistry, this droplet has a potential s ampling interface for such soluble constituents. This paper describes the c oupling of this passive sampling interface with a sequential spectrophotome tric analysis system, the behavior of the liquid droplet as a collection in terface using a wind-tunnel method and nitrogen dioxide as a test gas, and an evaluation of the performance of this experimental arrangement. Several aspects of the demonstration of its applicability for measuring ppb levels of gaseous nitrogen dioxide in a rural atmospheric environment were obtaine d by using a polyacrylate wind tunnel with satisfactory results.