Methods, devices, and systems using acoustic ejection for depositing fluid droplets on a sample surface for analysis

A method for preparing a sample surface for analysis, comprising:

• (a) providing a reservoir containing an analysis-enhancing fluid, wherein the analysis-enhancing fluid is comprised of an analysis-enhancing moiety and a carrier fluid, and the carrier fluid is comprised of a low volatility solvent that has a boiling point greater than 100° C. at a pressure of 1 atmosphere;
• (b) placing a surface of a sample in droplet-receiving relationship to the fluid-containing reservoir;
• (c) ejecting a droplet of the analysis-enhancing fluid from the reservoir such that the droplet is deposited on the sample surface at a designated site, wherein the ejected droplet has a volume of no greater than about 50 pL;
• and
• (d) subjecting the sample to conditions sufficient to allow the analysis-enhancing fluid to interact with the sample surface to render the sample surface suitable for analysis.

A method for preparing a sample surface for mass spectrometry analysis, comprising:

• (a) providing a reservoir containing an analysis-enhancing fluid, wherein the analysis-enhancing fluid is comprised of a mass spectrometry matrix material and a carrier fluid, and the carrier fluid is comprised of a low volatility solvent that has a boiling point greater than 100° C. at a pressure of 1 atmosphere;
• (b) placing a surface of a sample in droplet-receiving relationship to the fluid-containing reservoir;
• (c) ejecting a droplet of the analysis-enhancing fluid from the reservoir such that the droplet is deposited on the sample surface at a designated site;
• and
• (d) subjecting the sample to conditions sufficient to allow the analysis-enhancing fluid to interact with the sample surface to render the sample surface suitable for analysis.

A method for preparing a sample surface for mass spectrometry analysis, comprising:

• (a) providing a reservoir containing an analysis-enhancing fluid, wherein the analysis-enhancing fluid is comprised of a mass spectrometry matrix material and a carrier fluid, and the carrier fluid is comprised of a high volatility solvent that has a boiling point lower than 100° C. at a pressure of 1 atmosphere;
• (b) placing a surface of a sample in droplet-receiving relationship to the fluid-containing reservoir;
• (c) ejecting a droplet of the analysis-enhancing fluid from the reservoir such that the droplet is deposited on the sample surface at a designated site;
• and
• (d) subjecting the sample to a temperature lower than 25° C. and/or a pressure greater than 1 atmosphere to allow the analysis-enhancing fluid to interact with the sample surface and to render the sample surface suitable for analysis.

A method for preparing a sample surface for mass spectrometry analysis, comprising:

• (a) providing a reservoir containing an analysis-enhancing fluid, wherein the analysis-enhancing fluid is comprised of a mass spectrometry matrix material and a carrier fluid;
• (b) placing a surface of a sample in droplet-receiving relationship to the fluid-containing reservoir;
• (c) ejecting a droplet of the analysis-enhancing fluid from the reservoir such that the droplet is deposited on the sample surface at a designated site;
• and
• (d) subjecting the sample to an atmosphere that is at least about 30% saturated with the carrier fluid to allow the analysis-enhancing fluid to interact with the sample surface and to render the sample surface suitable for analysis.

A method for preparing a sample surface for mass spectrometry analysis, comprising:

• (a) providing a reservoir containing an analysis-enhancing fluid, wherein the analysis-enhancing fluid is comprised of a mass spectrometry matrix material and a carrier fluid;
• (b) placing a surface of a sample in droplet-receiving relationship to the fluid-containing reservoir;
• (c) ejecting a droplet of the analysis-enhancing fluid from the reservoir such that the droplet is deposited on the sample surface at a designated site;
• and
• (d) subjecting the sample to conditions such that the carrier fluid exhibits a volatility quotient of at least about 30 to allow the analysis-enhancing fluid to interact with the sample surface and to render the sample surface suitable for analysis.

A system for depositing an analysis-enhancing fluid on a surface of a sample, comprising:

• a reservoir containing an analysis-enhancing fluid, wherein the analysis-enhancing fluid comprises a mass-spectrometry matrix material and a carrier fluid, and the carrier fluid is comprised of a low volatility solvent that has a boiling point greater than 100° C. at a pressure of 1 atmosphere;
• an acoustic ejector comprising an acoustic radiation generator for generating acoustic radiation and a focusing means for focusing the acoustic radiation generated;
• a means for positioning the acoustic ejector in acoustic coupling relationship to the reservoir;
• and
• a means for positioning the sample such that a designated site on the sample surface is positioned in droplet-receiving relationship to the reservoir.