LIQUID DROPLET - A RENEWABLE GAS SAMPLING INTERFACE

As a gas stream flows across a liquid droplet, the soluble constituents contained in the gas diffuse to and dissolve in the liquid drop. From the viewpoint of analytical chemistry, this droplet is thus a potential sampling interface for such soluble constituents. The problem that needs to be solved relates to the manner of its incorporation in a chemical analysis system. This paper describes the coupling of this sampling interface with a sequential analysis system, demonstration of its applicability for the measurement of parts-per-billion levels of gaseous NH3, and a characterization of the performance of this experimental arrangement. Various aspects of the behavior of the liquid droplet as a collection interface are theoretically discussed and experimentally examined using NH3 and SO2 as test gases.