| 主权项 |
1. A sheath-flow interface for producing electrospray from a capillary comprising:
(a) a silica capillary configured to contain an analyte liquid, the capillary having an injection end configured to receive the analyte liquid and an uncoated distal end configured to expel analyte effluent, wherein the outer diameter of a segment of the distal end tapers to a reduced outer diameter within the range of about 20 μm to about 200 μm; (b) an electrospray emitter coaxially disposed surrounding at least the distal end of the capillary, the electrospray emitter having a distal end that is tapered to terminate at an opening, the opening being coaxially disposed in relation to the distal end of the capillary; and (c) a sheath liquid reservoir in liquid communication with an interior of the electrospray emitter, such that an electrically conductive sheath liquid can flow from the sheath liquid reservoir, through a connecting fixture intermediate the capillary and the electrospray emitter, across the distal end of the capillary, and through the opening at the distal end of the electrospray emitter; wherein the sheath liquid provides electrical contact between the capillary and the electrospray emitter, the sheath-flow interface is configured to produce a nanospray generated by electrokinetic flow of the sheath liquid mixed with the analyte effluent, and the electrokinetic flow is generated by an electric potential between the electrospray emitter and a target surface disposed adjacent, but not in physical contact with, the opening of the emitter. |
