2D-Gas Chromatography Time-of-Flight Mass Spectrometry (GC×GC-ToF-MS), has been utilised to characterise the composition of particulate matter exhaust emissions, in particularly Semi-volatile Organic Compounds (SVOC), which are difficult to be quantified due to their unstably partitioning between the gas and aerosol phases. This technique has demonstrated the capability of resolving specific components of the Unresolved Complex Mixture (UCM), the large “hump” that makes up approximately 95% of the area of the chromatogram.