Dual Nano-Electrospray and Mixing in the Taylor Cone

Anna Radionova,Peter J Derrick,David R Greenwood,Geoff R Willmott

doi:10.5478/msl.2016.7.1.21

Abstract

Dual-channel nano-electrospray has recently become an ionization technique of great promise especially in biological mass spectrometry. This unique approach takes advantage of the mixing processes that occurs during electrospray. Understanding in more detail the fundamental principles influencing spray formation further study of the origins of the mixing processes: (1) in a Taylor cone region, (2) in charged droplets or (3) in both environments. The dual-channel emitters were made from borosilicate theta-shape glass tubes (O.D. 1.2 mm) and had a tip diameters of less than 4 μm. Electrical contact was achived by deposition of a thin film of an appropriate metal onto the surface of the emitter. The experimental investigation of the Taylor cone formation in a dual-channel electrospray emitter has been carried out by injection of polystyrene beads (diameter 3 μm) at very low concentrations into one of the channels of the non-tapered theta-glass tubes. High-speed camera experiments were set up to visualize the mixing processes in Taylor cone regions for dual-channel emitters. Mass spectra from dual nano-electrospray are presented.

Highlights

Nano-electrospray was introduced by Wilm and Mann[1] little more than 20 years ago, and it was named to reflect the flow rate and size of a droplets produced by emitters
Similar flow patterns were obtained when particles were introduced into a single channel emitter, and in the results reported by Barrero et al.[9] for polystyrene beads of 5-micrometer size were introduced to ethanol
There was less sodium when theta-shape emitters were used, which was reflected in a higher intensity of EDTA In the first set of a short time scale experiments, metal-binding ligand EDTA at 10 mM was injected in one of the channels and a solution of CaCl2 at the same concentration was injected into the second channel

Summary

Introduction

Nano-electrospray (nano-ESI) was introduced by Wilm and Mann[1] little more than 20 years ago, and it was named to reflect the flow rate and size of a droplets produced by emitters. The dual-channel emitters were made from borosilicate theta-shape glass tubes (O.D. 1.2 mm) and had a tip diameters of less than 4 μm. The experimental investigation of the Taylor cone formation in a dual-channel electrospray emitter has been carried out by injection of polystyrene beads (diameter 3 μm) at very low concentrations into one of the channels of the non-tapered theta-glass tubes.

Results

Conclusion