A colorimetric method for the determination of oxides of nitrogen

Abstract

A method is described for determining oxides of nitrogen, and it has been applied to the gaseous products derived from initiating compositions. The oxides of nitrogen are absorbed from the sample into sulphuric acid, iron(II) sulphate is added, and the pink colour is measured. The interference effects of a number of gases such as hydrogen sulphide and sulphur dioxide have been investigated. The range of the method is 0·005 to 5 per cent. of oxides of nitrogen (calculated as nitrogen dioxide).