Electrospray ionisation source incorporating electrodynamic ion focusing and conveying

The control and transmission of charged entities in the intermediate to high pressure regime is of primary importance in areas such as atmospheric pressure ionisation. In an electrospray ionisation source where small apertures separate differentially pumped vacuum regions in the inlet systems to mass spectrometers, a large proportion of the available ion current is lost to the surrounding electrode structures. A new electrospray ionisation source, incorporating electrodynamic focusing and conveying of charged entities in two vacuum regions is described. The new source design incorporates ion accumulation and pulsed extraction to allow application in techniques such as Fourier Transform Ion Cyclotron Resonance and orthogonal time-of-flight where a pulsed ion source in required. The design of the new source is described and preliminary experimental results using an orthogonal time-of-flight configuration are presented. (C) 2008 Elsevier B.V. All rights reserved