Exhaust flow boosting for sampling probe for use in mass spectrometry systems and methods

A method for performing chemical analysis of a specimen, comprising:

• inserting the specimen into liquid within a sampling space of a sampling probe, the sampling probe comprising:
• an outer housing having an open end;
• a liquid supply conduit within the housing, the liquid supply conduit extending from an inlet end for coupling to a liquid supply source to an outlet end configured to deliver liquid to the sampling space at the open end of the housing, wherein the sampling space comprises a liquid-air interface through which the specimen is received within the liquid;
• and
• a liquid exhaust conduit within the housing, the liquid exhaust conduit extending from an inlet end in fluid communication with the sampling space to an outlet end, and the liquid exhaust conduit being configured to transport liquid from the sampling space through the outlet end of the liquid exhaust conduit at a flowrate range of 0.1 mL/min to 20 mL/min;
• entraining the liquid from the outlet end of the liquid exhaust conduit within a motive liquid to form a sample mixture, wherein the entraining the liquid from the outlet end of the liquid exhaust conduit within a motive liquid to form a sample mixture comprises:
• discharging the motive liquid into a suction chamber of a jet pump body through a nozzle at a pressure greater than about one atmosphere at a flowrate range of 0.01 mL/min to 10 mL/min, so as to draw liquid from the liquid exhaust conduit into the suction chamber;
• and
• transporting the sample mixture through a sample conduit extending from the suction chamber to an outlet end, the sample conduit comprising a converging portion that receives the sample mixture from the suction chamber and mixes the sample mixture therein, the converging portion extending from an upstream end adjacent the suction chamber to a downstream end and exhibiting a decreasing cross-sectional area along a length thereof, and the converging portion exhibiting a decreased cross-sectional area relative to a cross-sectional area of the suction chamber;
• discharging said sample mixture from the sample conduit into an ionization chamber so as to ionize one or more analyte species within the sample mixture;
• and
• performing mass spectrometric analysis on said one or more ionized analyte species.

A system for analyzing a chemical composition of a specimen, comprising:

• a sampling probe comprising:
• an outer housing having an open end;
• a liquid supply conduit within the housing, the liquid supply conduit extending from an inlet end for coupling to a liquid supply source to an outlet end configured to deliver liquid to a sampling space at the open end of the housing, wherein the sampling space comprises a liquid-air interface for receiving a specimen within the liquid in the sample space;
• and
• a liquid exhaust conduit within the housing, the liquid exhaust conduit extending from an inlet end configured to transport liquid from the sampling space to an outlet end;
• a jet pump body defining a suction chamber in fluid communication with the outlet end of the liquid exhaust conduit;
• a nozzle configured to discharge a motive liquid into the suction chamber at a pressure greater than about one atmosphere;
• a sample conduit extending from the suction chamber to an outlet end, the sample conduit configured to transport a sample mixture from the suction chamber;
• an ion source configured to receive the sample mixture from the sample conduit, and configured to discharge the sample mixture into an ionization chamber in communication with a sampling orifice of a mass spectrometer so as to form a sample plume;
• and
• a source of nebulizer gas surrounding a discharge end of the ion source and configured to generate a flow of nebulizer gas that surrounds the sample mixture as the sample mixture is discharged into the ionization chamber, to thereby shape and/or assist in desolvation of the sample plume,
• wherein discharge of the motive liquid into the suction chamber is configured to draw liquid from the liquid exhaust conduit so as to form the sample mixture.