An integrated system for liquid separation and electrospray ionization includes an emitter-enabled capillary column including an emitter portion and a column portion; and a retractable protective sleeve for covering and/or supporting the emitter portion along at least a portion of its axis. The protective sleeve is mounted around the emitter-enabled capillary column. The retractable protective sleeve is moveable to an extended position wherein a tip of the emitter portion is covered by the protective sleeve. A resilient member is provided to bias the protective sleeve towards the extended position. The protective sleeve is enclosed and moveable within an outer electrically conductive sheath adapted for insertion within a holder having a high-voltage contact point. The sheath is adapted to contact the high-voltage contact point and provide an electrical connection to enable the emitter-enabled capillary column to receive a high voltage. The sheath has a recess to receive the high-voltage contact point.