Joint quantification of PAH and oxy-PAH from standard reference materials (urban dust and diesel particulate matter) and diesel soot surrogate by GC-MS

The combustion of fossil fuels produces pollutants such as soot, which consists of carbonaceous particles whose emission is regulated by environmental laws. Soot is mainly formed from polycyclic aromatic hydrocarbons (PAH), through different reaction ways and, once formed, it can adsorb PAH on its surface. These compounds have an environmental importance due to their carcinogenic and mutagenic potential. In the last years, the oxygenated derivatives of PAH (oxy-PAH) have also been considered as dangerous since they have been found to be mutagenic for bacterial and human cells. Therefore, the purpose of this work was to quantify simultaneously selected PAH and oxy-PAH from different samples of soot. The quantification method involves Soxhlet extraction and subsequent concentration by rotary evaporation that allows to recover the analysed compounds from soot samples. The PAH and oxy-PAH were identified and quantified, by a single injection, using a gas chromatograph-mass spectrometer (GC-MS). The method showed a good repeatability using a diesel soot surrogate test sample, Printex-U. The validation process showed that most of the compounds are recovered between the values established for the Standard Reference Materials analysed, 1650b and 1649b. The values of the mass fraction of the oxy-PAH obtained in this work showed, in general, a good match with those indicated in other studies.