Fourier transform electrospray ion mobility spectrometry

The analytical merit of Fourier transform electrospray ionization ion mobility spectrometry (FT-ESI-IMS) was investigated. When compared with signal-averaged electrospray ionization ion mobility spectrometry (SA-ESI-IMS) an increase in both signal/noise ratio (SIN) and ion mobility resolving power was observed for the FT mode of operation. Using angiotensin II, glucosamine, n-tetradecylamine and gramicidin s as test compounds, electrospray ion mobility spectra were demonstrated in both modes under identical operating conditions. Both SIN and IMS resolving power were measured as a function of gate pulse width. Although SIN enhancement using FT was not as great as predicted from ideal conditions, a model was developed to explain this discrepancy. Not only did the FT operating mode enhance SIN and IMS resolving power, it also served to evaluate the stability of the electrospray process.