Global shipping is a source of particulate matter and organic pollutants. The molecular composition of fossil fuels and their combustion products is high complex. For characterization, the ultra-high resolution of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is applied. The focus of this work is developing a method for the investigation of combustion aerosols on the molecular level by use of direct thermal desorption atmospheric pressure photoionization FT-ICR MS.