Determination of atmospheric sulfur dioxide without tetrachloromercurate(ii): Further refinements of a pararosaniline method and field application

Abstract

Results are presented for the field application of a pararosaniline method which determines sulfur dioxide by utilizing a nontoxic thermally stable dilute formaldehyde absorber buffered at pH 4. Parallel results by the Federal Reference Method are reported. Further refinements of the pararosaniline procedure including dye reagent purification and inclusion of a trichloroacetic acid buffer system are described. Merits and limitations of direct and reverse reagent addition are discussed. © 1981 Air & Waste Management Association.