Enclosed desorption electrospray ionization probes and method of use thereof
The invention generally relates to enclosed desorption electrospray ionization probes, systems, and methods. In certain embodiments, the invention provides a source of DESI-active spray, in which a distal portion of the source is enclosed within a transfer member such that the DESI-active spray is produced within the transfer member.
1. A method for analyzing a sample, the method comprising:
directing a discharge from a source at a first velocity to sample on a substrate, wherein the discharge interacts with the sample to desorb an analyte from the sample and the discharge with the desorbed analyte is directed at a second velocity to a mass spectrometer, the second velocity being higher than the first velocity; and
analyzing the desorbed analyte in the mass spectrometer.
2. The method of claim 1 , wherein the sample is a tissue sample.
3. The method of claim 2 , wherein the analyte is indicative of a disorder.
4. The method of claim 3 , wherein the disorder is cancer.
5. The method of claim 2 , wherein the analyte is a lipid.
6. The method of claim 1 , wherein the source is a desorption electrospray ionization (DESI) source.
7. The method of claim 6 , wherein DESI source is operably associated with a counter-flowing gas source.
8. The method of claim 7 , wherein the DESI source is enclosed within member that is operably associated with the mass spectrometer and the counter-flowing gas source.
9. The method of claim 1 , wherein the sample is contacted multiple times.
10. The method of claim 9 , wherein the multiple analyses are conducted, each analysis based on each contacting of the sample.
11. A mass spectrometry apparatus comprising:
a discharge ionization source; and
a counter-flowing gas source that is operably associated with the discharge ionization source in a manner that a discharge from the discharge ionization source is directed at a first velocity to sample on a substrate, wherein the discharge interacts with the sample to desorb an analyte from the sample and the discharge with the desorbed analyte is directed at a second velocity to a mass spectrometer, the second velocity being higher than the first velocity.
12. The mass spectrometry apparatus of claim 11 , wherein the source is a desorption electrospray ionization (DESI) source.
13. The mass spectrometry apparatus of claim 12 , wherein the DESI source is enclosed within member that is operably associated with the mass spectrometer and the counter-flowing gas source.
14. The mass spectrometry apparatus of claim 12 , wherein the counter-flowing gas source is a pump.
15. The mass spectrometry apparatus of claim 14 , wherein the member is a U-shaped member comprising a distal portion that is proximate the substrate, a middle portion, and a proximal portion.
16. The mass spectrometry apparatus of claim 15 , wherein the DESI source is associated with the distal portion, the middle portion is associated with a mass spectrometer, and a proximal portion is associated with the pump.
17. The mass spectrometry apparatus of claim 16 , wherein a distal portion of the DESI source is sealed within the distal portion of the U-shaped member.
18. The mass spectrometry apparatus of claim 11 , further comprising the mass spectrometer.
19. The mass spectrometry apparatus of claim 11 , wherein the mass spectrometer is a miniature mass spectrometer.
20. The mass spectrometry apparatus of claim 11 , wherein the discharge ionization source operates without a voltage.