Ozone analysis with the Mini-Adak II.

Abstract

Accurate, continuous measurements of ozone are extremely important in air pollution studies, since the oxidant level correlates with the degree of irritation, visibility and plant injury in Los Angeles-type smog. Although several instruments have been designed specifically for continuous ozone analysis, a single purpose instrument for each pollutant is expensive. A multi-purpose analyzer, capable of analyzing the atmosphere for a number of important contaminants, could reduce significantly the capital investment required by an air pollution group for numerous single-purpose instruments. Such an analyzer, potentially capable of analyzing and recording any reagent-soluble and -reactive pollutant for which a suitable colorimetric analytical methods exists, was developed. This analyzer, the Mini-Adak, comprises two functional parts: a recording, flow colorimeter, and an air-reagent contacting system. Because of the inherent versatility of the Mini-Adak analyzer and the stability and specificity of the sodium diphenyl-aminesulfonate ozone reagent, the simplicity of the phenolphthaline reagent, a study was undertaken to determine the suitability of these reagents for ozone analysis with a multi-purpose, automatic analyzer. This paper describes the use of NaDS and phenolphthalin in a Mini-Adak II analyzer. The response of the reagent to some interfering compounds is discussed and comparative laboratory data obtained with the neutral KImore » reagent are presented.« less