Basic equations of Mass spectrometry Ions kinetic e function of mv=zv accelerating voltage(v)and charge(z V ball centrifugal F=my/ r Centrifugal force force F=BEV L Applied magnetic field trimetal force rentz force Balance as ion goes mv/r=Bzv] through flight tube Combine equations to obtain m/z=br/2V Fundamental equation of mass spectrometry Change ' mass-to-charge(m/z)ratio by m/z =m/ changing V or changing B for singly charged ions NOTE: if B, v, z constant, then r-radius of circular ion pathBasic Equations of Mass Spectrometry 1 2 2 mv zV = 2 F mv R = / F Bzv = 2 mv R Bzv / = 2 2 m z B R V / / 2 = Ion’s kinetic E function of accelerating voltage (V) and charge (z). Centrifugal force Applied magnetic field Lorentz force Balance as ion goes through flight tube Fundamental equation of mass spectrometry Combine equations to obtain: Change ‘ mass-to-charge’ (m/z) ratio by changing V or changing B. NOTE: if B, V, z constant, then: r m  m/z = m/e for singly charged ions r- radius of circular ion path r r r