Characterization of purified biomarker compounds using time of flight-secondary ion mass spectrometry (ToF-SIMS)

We demonstrate that the ion probe technique of time of flight-secondary ion mass spectrometry (ToF-SIMS) is capable of identifying purified organic compounds in situ and could augment GC-MS analysis on small geological samples. ToF-SIMS has been applied to a number of purified organic compounds including polycyclic aromatic hydrocarbons, nitrogen-containing heterocyclics, n-alkanes and isoprenoids. It is found that ToF-SIMS allows detection of individual poly- and heterocyclic aromatic hydrocarbons from the presence of their molecular (or near molecular) ions. The identification of individual methylated and non-methylated aliphatic hydrocarbons has proven more difficult, as a molecular ion is not always produced. All cyclic and some aliphatic compounds could be identified, even in complex mixtures.