The hydrothermal degradation of plastics results in the gaseous product consisted of C₁C₆ hydrocarbons. On that basis, this study presents the development and validation of a GC–MS method for the simultaneous determination of methane, carbon dioxide, ethene, ethane, propene, propane, 1-butene, butane, 1-pentene, pentane, 1-hexene, and hexane. The method developed was shown to be selective for all components. Moreover, linear concentration ranges along with 95% confidence intervals were determined. Furthermore, the limits of quantification for each component were determined. It was also shown that the method had satisfactory accuracy and precision for the determination of gaseous species in a real sample. The method was therefore shown to be useful for a real sample analysis, where gaseous species were formed upon the degradation of low-density polyethylene (LDPE) with supercritical water technology. The method was applied and tested on three gas samples produced by the degradation of LDPE raw material at different reaction times. The gas samples were rich in methane and the amount thereof depended on the reaction time; therefore, with a longer reaction time more methane was produced.

塑料的水热降解导致气态产物由C ₁ C _6组成碳氢化合物。在此基础上，本研究提出了同时测定甲烷，二氧化碳，乙烯，乙烷，乙烷，丙烯，丙烷，1-丁烯，丁烷，1-戊烯，戊烷，1-己烯的GC-MS方法的开发和验证和己烷。事实证明，开发的方法对所有组件均具有选择性。此外，确定了线性浓度范围以及95％的置信区间。此外，确定了每种成分的定量限。还表明，该方法对于测定真实样品中的气态物种具有令人满意的准确性和精密度。因此，该方法显示出对实际样品分析有用，该分析中使用超临界水技术降解低密度聚乙烯（LDPE）时会形成气态物质。该方法适用于在不同反应时间降解LDPE原料产生的三种气体样品。气体样品中富含甲烷，其数量取决于反应时间。因此，反应时间越长，产生的甲烷就越多。