Thermal Energy Distribution Observed in Electrospray Ionization

A new method was developped which fits a thermal internal energy distribution to ions formed by electrospray ionization. The molecular ion survival yield was measured and determined by RRKM calculations as a function of temperature. The "characteristic" temperature was determined when the calculated and measured molecular survival yields were equal. The validity of the method was also checked performing blackbody infrared radiation and on-resonance excitation experiments on a Fourier transform ion cyclotron resonance instrument with benzylpyridine salts and leucine enkephalin.