Improved Impinger Air Sampling Method by Using Highly Hydrophilic Surface and its Application to Automatic Monitor for Acidic or Basic Contaminations in Cleanroom Air

Abstract

We have developed an automatic air monitoring apparatus for measuring trace amounts of acidic or basic contaminants in clean room air. The apparatus includes an ion chromatograph and uses a new air sampling method. Its absorbing vessel is a tube made of quartz glass whose inner surface is cleaned with ultraviolet light so as to be highly hydrophilic. When an air sample is bubbled into 6 ml of absorbing water, the bubbles rise stably to the upper part of the tube and the inner surface is coated with water film. Since the air sample has sufficient contact with the absorbing water, analytical components can be effectively absorbed into the water. It takes 27 min to analyze a sample consisting of organic and inorganic acid of more than 0.1 μg/m³ in air.