Development and evaluation of a nano-electrospray ionisation source for atmospheric pressure ion mobility spectrometry

Abstract

A nano-electrospray ionisation source has been designed and constructed for a high temperature ion mobility spectrometer. The drift cell was modified by replacement of the ⁶³Ni atmospheric pressure chemical ionisation source with a tube lens/desolvation region and operated using commercial nano-electrospray capillaries. Ions were introduced into the drift region via a Bradbury–Nielson gate (pulse width 50 μs, repetition period 20 ms). A unidirectional flow of nitrogen was used as the drift gas at temperatures in the range 100–150 °C to aid desolvation. The performance of the nano-electrospray ion source has been demonstrated for analytes including crown ethers, amino acids and peptides. Reduced mobilities determined by nano-ESI were consistent with those reported using a ⁶³Ni ion source.