TG-MS Analysis\nfor Elemental Composition of Organic\nMatters and Their Structural Properties

A novel approach for determining the elemental content\nof organic\nmatter through thermal gravimetric analysis coupled online with a\nmass spectrometer (TG-MS) is disclosed. This method not only yields\nresults equivalent to ASTM analysis but also provides insight into\nthe covalent bond structure within the sample. The principle of this\ntechnique consists of the combustion of organic matter in an oxygen-enriched\nenvironment within the thermogravimetric (TG) system. The gases generated\nduring combustion, including carbon-containing gases such as CO<sub>2</sub> and CO, hydrogen-containing gases such as H<sub>2</sub>O,\nnitrogen-containing gases such as NO<sub>2</sub> and NO, and sulfur-containing\ngases such as SO<sub>2</sub>, are then analyzed using online MS. Quantitative\nanalysis of these gases is accomplished via an external standard method,\nfacilitating the determination of the elemental content of the organic\nmatters. The experiment employed a temperature-programmed heating\nrate of 10 °C/min, a carrier gas flow rate of 100 mL/min, and\nan oxygen concentration of 50% by volume. We conducted tests on a\nrange of 23 samples, including coal, heavy oil, oil shale, and biomass.\nThe results for coal, oil shale, and biomass samples were consistent\nwith ASTM standards, while the heavy oil samples demonstrated slightly\nlower values compared with ASTM methods. Furthermore, we probed into\nthe mass loss and gas generation processes that occur during the combustion\nof samples, and these results enhance the understanding of the mechanism\nof organic matter combustion as well as that of the covalent bond\nstructure of organic matters.