Three-dimensional molecular imaging by infrared laser ablation electrospray ionization mass spectrometry
The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation with electrospray ionization (ESI).
1. A method of laser ablation electrospray ionization mass spectrometry for three-dimensional imaging of a sample having a water content, the method comprising:
ablating the sample with a mid-infrared laser pulse to generate an ablation plume;
intercepting the ablation plume with an electrospray to produce ions; and
analyzing the ions by a mass spectrometer comprising a scanning apparatus to generate a three-dimensional image of the sample;
wherein each laser pulse has a laser energy that is absorbed by the water in the sample.
2. The method of claim 1 , wherein the sample comprises a target, and the method is characterized by negligible photochemical damage to the target by the laser energy.
3. The method of claim 2 , wherein the target comprises a biomolecule selected from a peptide, a metabolite, a lipid an oligosaccharide, a protein, DNA, and an xenobiotic.
4. The method of claim 1 comprising one of lateral scanning of the sample, depth profiling of the sample, and a combination thereof.
5. The method of claim 1 comprising adding an aqueous solution to the sample.
6. The method of claim 1 comprising ablating the sample in the presence of a reactant in one of a gas phase, the sample, the electrospray, and combinations thereof.
7. The method of claim 1 comprising measuring a size and a depth of the ablation in the sample by the laser pulse, and adjusting one of the laser pulse, the laser energy, the wavelength, a working distance, and combinations thereof.
8. The method of claim 1 comprising generating a spatial distribution image of one or more of the ions.
9. The method of claim 1 comprising generating a co-localization image of at least one of a first ion and a second ion.
10. The method of claim 9 , wherein the co-localization image comprises one of a lateral co-localization image, a cross-sectional co-localization image, and a combination thereof.
11. The method of claim 1 , wherein the sample is a live sample.
12. The method of claim 1 , wherein the sample is a viable sample.
13. The method of claim 1 comprising an in situ method of laser ablation electrospray ionization mass spectrometry for three-dimensional imaging of a sample having a water content, the in situ method comprising:
ablating the sample with a mid-infrared laser pulse to generate an ablation plume;
intercepting the ablation plume with an electrospray to produce ions; and
analyzing the ions by a mass spectrometer comprising a scanning apparatus to generate a three-dimensional image of the sample;
wherein each laser pulse has a laser energy that is absorbed by the water in the sample.
14. The method of claim 1 comprising an in vivo method of laser ablation electrospray ionization mass spectrometry for three-dimensional imaging of a sample having a water content, the in vivo method comprising:
ablating the sample with a mid-infrared laser pulse to generate an ablation plume;
intercepting the ablation plume with an electrospray to produce ions; and
analyzing the ions by a mass spectrometer comprising a scanning apparatus to generate a three-dimensional image of the sample;
wherein each laser pulse has a laser energy that is absorbed by the water in the sample.
15. The method of claim 1 comprising generating an optical image of the sample.
16. A laser ablation electrospray ionization mass spectrometry device for three-dimensional imaging of a sample having a water content, the device comprising:
a pulsed, mid-infrared laser to emit energy at the sample to ablate the sample and generate an ablation plume;
a translation stage;
at least one of a lens, a mirror, and an optical fiber to focus the laser energy;
an electrospray apparatus to produce an electrospray to intercept the ablation plume to produce ions;
a mass spectrometer having an ion transfer inlet to capture the produced ions; and
a scanning apparatus to generate a three-dimensional image of the sample;
wherein each laser pulse has a laser energy that is absorbed by the water in the sample.
17. The device of claim 16 , wherein the scanning apparatus comprises a computer.
18. The device of claim 17 , wherein the computer is programmed for one of lateral scanning of the sample, depth profiling of the sample, and a combination thereof.
19. The device of claim 17 , wherein the computer is programmed to position the translation stage and collect data corresponding to the position of the translation stage.
20. The device of claim 17 , wherein the computer is programmed to generate the three-dimensional image of the sample.