The analysis aims to obtain quantitative characteristics (concentration, peak areas or heights) of the common aromatic biomarkers, in the aromatic fraction of oil samples. Internal standard is used for quantitation. The analysis is performed in an Agilent 7890/7650 GC/MS system with a capillary column in both Selective Ion Monitoring (SIM) and Full scan modes. Requires oil or extract concentration and fractionation using GE_405, GE-407 and GE_408.