*3.2.2 Sequential analysis of metallic and organic constituents in geological samples*

Besides metallic constituents, organic constituents are also important for geological samples [38]. For example, biomarkers, such as alkanes, aromatic hydrocarbons, terpenoids, steroids, fatty acids, porphyrins, and so on, are helpful in identifying the source of organic matters, inferring the redox conditions of depositional and early diagenetic stages, and in reflecting thermal maturity of sediments. Thus, a method is urgent that could simultaneously analyze the metallic and organic constituents, which would not only provide information on metallic and organic constituents but could also establish the relationship between the metallic and organic constituents. Recently, we have started research to simultaneously analyze the metallic and organic constituents in fossils, soil, PM2.5, tissue, alloy, etc. by sequential ionization MS.
