Continuous-flow sample introduction for field desorption/ionization mass spectrometry

We introduce continuous-flow field desorption (FD) for improved spectral quality, higher sample throughput, and simpler interface to sample handlers and chromatographic equipment. A recently developed commercial FD probe with integral fused-silica capillary allows sample dosing in situ, without probe removal and reinsertion. A stable FD-generated ion current can be sustained for longer than an hour by continuous deposition of analyte solution on the FD emitter heated and at high voltage. Continuous-flow FD allows ensemble averaging of up to 100 Fourier transform ion cyclotron resonance (FT-ICR) mass spectra, in contrast to the traditional emitter dosing technique. Continuous-flow FD is amenable to interface with liquid chromatography (LC) and/or automated sample injectors. Copyright (C) 2004 John Wiley Sons, Ltd.