CPC G01N 33/492 (2013.01) [G01N 1/28 (2013.01); G01N 1/286 (2013.01); G01N 33/48714 (2013.01); G01N 33/48785 (2013.01); G01N 33/491 (2013.01); H01J 49/0009 (2013.01); H01J 49/0027 (2013.01); H01J 49/16 (2013.01); G01N 1/10 (2013.01); G01N 2001/2893 (2013.01)] | 11 Claims |
1. A method for analyzing a sample comprising:
preparing a mixture of a sample with a controlled amount of an internal standard;
contacting the mixture to a porous substrate that tapers to at least one tip, wherein the porous material is kept separate from a flow of solvent and the probe operates without pneumatic assistance;
applying a high voltage to the porous material such that an electric field is generated at a tip of the material so as to generate ions of an analyte and ions of the internal standard that are expelled from the porous material; and
analyzing the expelled ions.
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