CPC H01J 49/0431 (2013.01) [G01N 27/44717 (2013.01); G01N 27/4473 (2013.01); H01J 49/165 (2013.01); G01N 30/7266 (2013.01)] | 10 Claims |
1. A method for analyzing a sample, the method comprising:
providing a liquid sample reservoir that is coupled to a first electrode;
providing a power source coupled to the first electrode;
providing a mass spectrometry probe comprising: a hollow body comprising a distal tip; and a second electrode, wherein the second electrode is disposed within the hollow body;
providing an electrically conductive hollow conduit that is coupled at a first end to the liquid sample reservoir, wherein the electrically conductive conduit has a length such that it extends into the hollow body of the mass spectrometry probe;
introducing a liquid sample comprising a small molecule and a plurality of liquid-phase ions into the liquid sample reservoir;
causing the liquid sample to be moved from the liquid sample reservoir and into the hollow body via the hollow conduit such that a gap is maintained between the liquid sample and the second electrode;
applying a positive voltage to the hollow conduit via voltage from the first electrode being applied to the liquid sample reservoir needle which operably applies the voltage to the hollow conduit, while transporting the liquid sample from the liquid sample reservoir through the hollow conduit and into the hollow body, wherein the liquid sample is polarized as the liquid sample flows through the hollow conduit and into in the hollow body;
inductively applying a negative voltage from the second electrode across the gap to the liquid sample, thereby causing the plurality of liquid-phase ions to separate from the small molecule within the hollow body but not within the hollow conduit;
terminating the negative voltage from the second electrode while maintaining the positive voltage to the hollow conduit to thereby cause the small molecule to be emitted from the distal tip and become ionized; and
analyzing the ionized small molecule in a mass spectrometer.
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