Monoethanolamine as an absorbing reagent for the spectrophotometric determination of atmospheric sulphur dioxide

Abstract

The possible use of monoethanolamine as an absorbing reagent for sulphur dioxide has been investigated. The proposed reagent has an absorption efficiency of about 100% and is superior to the sodium tetrachloromercurate method with respect to ease of manipulation, speed, stability of absorbed sulphur dioxide and the use of stable and readily available pure and non-toxic reagents. The effects of reagent concentration, flow-rate and temperature on the absorption of sulphur dioxide were studied. The absorbed sulphur dioxide was subsequently determined spectrophotometrically using p-aminoazobenzene - formaldehyde reagent in hydrochloric acid medium. The interference of nitrogen dioxide is eliminated by the use of sulphamic acid. The procedure is suitable for air pollution studies.