Electrophoretic mass spectrometry probes and systems and uses thereof

A method for analyzing a sample, the method comprising:

• providing a mass spectrometry probe comprising:
• a hollow body comprising a distal tip;
• an electrically conductive hollow conduit operably coupled to a reservoir and a power source, wherein the hollow conduit is configured to transport a liquid sample into the hollow body and polarize the liquid sample as the liquid sample flows through the hollow conduit and into in the hollow body;
• and an electrode, wherein the electrode and the hollow conduit are disposed within the hollow body;
• introducing a liquid sample comprising a target analyte and a plurality of liquid-phase ions from the reservoir and into the hollow body via the hollow conduit;
• applying a voltage to the hollow conduit while transporting the liquid sample from the reservoir through the hollow conduit and into the hollow body and inductively applying voltage from the electrode to the liquid sample, thereby causing the plurality of liquid-phase ions to separate from the target analyte;
• terminating the voltage from the electrode while maintaining the voltage to the hollow conduit to thereby cause the target analyte to be emitted from the distal tip and become ionized;
• and
• analyzing the ionized target analyte in a mass spectrometer.