Analytical merit of electrospray ion mobility spectrometry as a chromatographic detector

Electrospray ionization ion mobility spectrometry (ESI‐IMS), a technique which has only recently become analytically useful, has been evaluated for use as a detector for microbore liquid chromatography and capillary electrophoresis. Figures of merit for ESI‐IMS were determined. Detection limits as low as 1 × 10−15 mol s−1 were measured, with a linear response range of 3 to 4 orders of magnitude and with reproducibility within 3% (relative standard deviation of peak area). Gradient elution with water/methanol mobile phase did not perturb chromatographic baseline, compound response, or product ion mobility. Both positive and negative ion mobility spectra for more than 30 compounds demonstrated the sensitivity of ESI‐IMS response to a wide range of analytes. Finally, the concept of using ESI‐IMS as an ionization source for gasphase samples was presented, potentially unifying detector application for both gas and liquid chromatography.