Analysis of a tire-derived oil using GC × GC – TOF/MS for better identification and grouping of hydrocarbon compounds

摘要

A tire-derived oil (TDO) consists of many types of hydrocarbons such asmono-aromatics (MAHs), di-aromatics (DAHs), poly-aromatics (PAHs) and polararomatics(PPAHs). Previously, a GC/MS has been used to analyze the components inTDOs, and 38 hydrocarbon species were found and identified. However, the drawbackof a regular GC/MS is that it cannot separate the hydrocarbon species with the sameretention time because boiling points, vapor pressures and mass spectral fragmentationpatterns are indistinguishable. Therefore, hundreds of hydrocarbons in the oil could notbe observed and identified due to the overlapped mass spectra. At present, no work hasbeen reported on analysis of a tire-derived oil using Two-Dimensional GasChromatography coupled with a Time-of-Flight Mass Spectrometry (GC x GC / TOFMS)for hydrocarbon species. The objective of this work was to examine thecomponents in a tire-derived oil, and completely report the results in terms of 2D(contour plot) and 3D (surface plot) plots of total ion chromatograms for outstandinggroups of hydrocarbon species such as saturated hydrocarbons (SATs), olefins (OLEs),terpenes (TERs), MAHs, DAHs, PAHs, and PPAHs, including sulfur compounds.Maltenes (liquid fractions without asphaltene) were collected and analyzed by using aSIMDIST GC, and GC × GC / TOF-MS. As a result, the SATs consists of aliphatichydrocarbons starting at C13, C14 to C16. The OLEs consists of di-olefins and triolefins.The TERs consists of Carene and Limonene. The MAHs is categorized intotwo groups; that are, (a) mono-aromatics with saturated substituents (MAHs-SS) suchas indanes, alkylbenzenes, and tetralins, and (b) mono-aromatics with unsaturatedsubstituents (MAHs-US) such as indenes and alkenylbenzene. The DAHs consists ofnaphthalene and alkylnaphthalenes. The PAHs consists of phenanthrene, anthracene,fluorene, and pyrene. Finally, the PPAHs consists of thiophenes, benzothiohenes, anddibenzothiophenes.