“…In FI, however, an electron is removed from an analyte molecule through tunneling and, as the resulting molecular ion has little excitation, it is considered to yield little fragmentation. The history of FI itself is relatively long, and its application to organic molecules can be dated back to the 1960s . As ionization efficiency is very low in FI, however, a relatively limited number of GC/MS applications were reported prior to recent advances in instrumentation, including high‐scan speed, high‐sensitivity and high‐resolution time‐of‐flight (TOF) mass analyzers .…”