Abstract
An oxygen bomb method has been used for both the calorimetry and the decomposition procedure for chemical analyses of organic matters. As a fundamental study for applying the method to chemical analyses, gases and aqueous solutions after combustion of polyethylene in the bomb were analyzed by mass spectrometry and ultraviolet spectrophotometry. One gram of the sample was wrapped up in a sheat of rice paper, and fastened with cotton thread passing through the platinum coil between the electrodes.
The results obtained were as follows :
(1) Experimental values of compositions of gases both before and after the combustion were in fairly good agreement with the theoretically calculated values.
(2) Average amounts of nitric acid and nitrous acid in the bomb after every combustion were 80 and 3 mg. respectively. The amounts of these acids were prominently decreased by evacuating the bomb before filling up oxygen.
(3) These nitrogenous acids are predominantly derived from the nitrogen in the atmospheric air initially present in the bomb, rather than that contained in the oxygen supplied.
(4) In either case with or without evacuation of the air in the bomb, the conversion ratio of nitrogen to the acids was about 5 mole percent, and the mole percentage of nitrous acid in the mixed acids was between 4 and 5.
