Direct determination of polycyclic aromatic hydrocarbons in environmental matrices using laser desorption laser photoionization time-of-flight mass spectrometry

A series of environmental samples contaminated with polycyclic aromatic hydrocarbons (PAHs) were analysed using laser desorption laser photoionization time-of-flight mass spectrometry (L2TOFMS). Laser desorption removes the requirement for any sample pre-treatment and selective laser photoionization results in mass spectra containing signals corresponding principally to the contaminant PAH species. The methodology is based on the spatial and temporal separation of these evaporation and ionization steps. The instrument used is able to perform rapid, selective sample screening of contaminated soils, engine oil, coal soot and coal-tar creosote. The resulting fingerprint mass spectra indicate both the presence and composition of the PAHs in the matrices with instrumental detection limits in the sub-ppm range.