Determination of C1[sbnd]C6 hydrocarbons in gaseous plastic degradation products by GC–MS method

Abstract

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.