Why use perfluorotributylamine as standard tuning compound in mass spectrum?

Before starting a mass spectrometer (MS) and processing samples, the ion source voltage, quadrupole focusing, and mass axis alignment must be adjusted using a standard spectrum generated by Perfluorotributylamine (PFTBA). This process is called tuning. So why use PFTBA as a standard tuning compound?

The image above shows the mass spectra of perfluorotributylamine, which exhibits the following characteristics: simple ionization results and a wide signal peak range. Ordinary hydrocarbon compounds undergo complex carbon-hydrogen bond breaking, hydrogen transfer, and intramolecular rearrangement during ionization, resulting in a mass spectrum filled with numerous small fragment peaks that are difficult to distinguish. The mass numbers of PFTBA characteristic peaks also differ significantly from those of common background substances in the laboratory. Furthermore, PFTBA's core characteristic peaks include m/z 69, m/z 219, and m/z 502, covering the molecular weight range of most conventional gas chromatography analyses.