Agradecimentos: The authors wish to thank CAPES (Coordination for the improvement of higher education personnel) for research fellowship and INCTBio (National Institute of Science and Technology in Bioanalytics / FAPESP + CNPq) for research support. The authors also thank Prof. Elia Psillakis (Technical University of Crete, Greece), who kindly supplied the hardware for Vac-HSSPME and Prof. Leandro W. Hantao (University of Campinas) for provide access to equipment and laboratory resources Ver menos

Abstract: Vacuum-assisted headspace solid phase microextraction (Vac-HSSPME) with high temperature of extraction was used for source-rock analysis. Optimization of extraction conditions was performed by Doehlert experimental design (DD) in gas chromatography coupled to mass spectrometer detector (GC–MS). Samples from the same oil well were mixed to obtain a mean stratigraphic characteristic for extraction optimization. Source-rock samples were analyzed in the DD optimal conditions and the proposed Vac-HSSPME+GC–MS method was compared to the classical procedure (SARA). The identification of important biomarkers like steranes and pentacyclic terpanes was possible. Fingerprint comparison between both methods shows similarity for steranes profile of overall chromatographic signal and compounds distribution. Also, it was possible to assess theoretical kinetic considerations for the system, as it differs from most conditions reported in literature. Furthermore, no organic solvent was used during the extraction or analysis with Vac-HSSPME. Classifying the procedure as a green methodology, while being faster and cheaper for oil bearing source-rock analyses Ver menos