Electron impact ionisation of encapsulated 99mTc@C60 and 99mTc@C70

The present study shows simultaneous surface ionisation and electron impact ionisation during the formation and investigation of endohedral fullerenes 99mTc@C60 and 99mTc@C70. The endohedral fullerenes were generated using a mass spectrometer with a triple rhenium filament as an ion source. The ionisation energies (IE) determined were: 8.52 ± 0.25 eV for 99mTc@C60 and 9.57 ± 0.25 eV for 99mTc@ C70.