Elementary analysis of nitrogen using strong phosphoric acid and Dumas method

One of the authors has already published a method of determination of elementary nitrogen by use of strong phosphoric acid-potassium iodide. Although this method showed various merits, it was unutilizable for determination of nitrogen in pyridine ring. In order to elucidate its reason and to find a clue to finding the possibility of its application, mass spectrometry and chemical analysis of a gas collected in the azotometer have been carried out to confirm whether or not the gas is nitrogen. The result indicated that the nitrogen in a pyridine ring can be analysed by heating at about 255°C, but it is nccessary to remove the by-product oxygen. Thus, the gas in the azotometer is found to be a mixture of nitrogen and nitrous oxide and this tendency was the same in the Dumas method.