System and method of analysis of a protein using liquid chromatography-mass spectrometry

1. An electrospray ionization source, comprising:

a container having a cap, wherein the cap has an inlet line port and an outlet line port, wherein the container comprises an organic solvent and a base;

a sheath gas inlet line for providing a sheath gas to the inlet line port; and

a modified desolvation gas outlet line capable of connecting the outlet line port to a sheath gas inlet of an electrospray ionization probe,

wherein the electrospray ionization probe is operated in positive ion mode, wherein the organic solvent and base are capable of reducing a charge state of an analyte ion.

2. The electrospray ionization source of claim 1 , wherein the organic solvent is acetonitrile.

3. The electrospray ionization source of claim 1 , wherein the base is triethylamine.

4. The electrospray ionization source of claim 1 , wherein the electrospray ionization probe comprises an auxiliary gas inlet.

5. The electrospray ionization source of claim 4 , wherein the auxiliary gas inlet is supplied with an auxiliary gas.

6. The electrospray ionization source of claim 1 , wherein the electrospray ionization probe comprises an electrospray emitter needle, a sheath gas flow plumbing, and an auxiliary gas flow plumbing.

7. The electrospray ionization source of claim 6 , wherein the electrospray ionization probe is configured to direct flow in the sheath gas flow plumbing coaxially to the electrospray emitter needle.

8. The electrospray ionization source of claim 6 , wherein the electrospray ionization probe is configured to direct the flow in the auxiliary gas flow plumbing coaxially to the electrospray emitter needle.

9. The electrospray ionization source of claim 1 , wherein the sheath gas inlet line is partially inserted into to the inlet line port.

10. The electrospray ionization source of claim 1 , wherein the modified desolvation gas outlet line is partially inserted into to the outlet line port.

11. The electrospray ionization source of claim 1 , wherein the sheath gas flows from the sheath gas inlet line through the container containing an organic solvent into the desolvation gas outlet line.

12. The electrospray ionization source of claim 1 , wherein the container is surrounded by a second container.

13. The electrospray ionization source of claim 1 , wherein the electrospray ionization source is capable of being connected to a liquid chromatographic system.

14. A method of characterizing a protein in a sample, comprising:

supplying the sample to an inlet of an electrospray ionization source; wherein the electrospray ionization source comprises

a container having a cap, wherein the cap has an inlet line port and an outlet line port, wherein the container comprises an organic solvent and a base;

a sheath gas inlet line for providing a sheath gas to the inlet line port; and

a modified desolvation gas outlet line capable of connecting the outlet line port to a sheath gas inlet of an electrospray ionization probe;

generating ions of components of the protein in the sample at an outlet of the electrospray ionization source; and

analyzing the ions using a mass spectrometer to identify the components of the protein to characterize the protein,

wherein the electrospray ionization probe is operated in positive ion mode, and wherein the organic solvent and base reduce a charge state of the ions.

15. The method of claim 14 , wherein characterizing the protein comprises conducting an intact mass analysis.

16. The method of claim 14 , wherein characterizing the protein comprises conducting a peptide mapping analysis.

17. The method of claim 14 , wherein the electrospray ionization source is provides an electrospray with a solvent flow rate of greater than about 5 μL/min.

18. A liquid chromatography mass spectrometry system, comprising:

a liquid chromatography device configured to direct a flow of a sample to an electrospray ionization source;

wherein the electrospray ionization source comprises a container having a cap, wherein the cap has an inlet line port and an outlet line port, wherein the container comprises an organic solvent and a base;

a sheath gas inlet line for providing a sheath gas to the inlet line port; and

a modified desolvation gas outlet line capable of connecting the outlet line port to a sheath gas inlet of an electrospray ionization probe; and

wherein the electrospray ionization source is configured to charge and desolvate the sample to form ions of components of the sample; and

a mass spectrometry device configured to receive the ions and characterize mass to charge ratio of the ions,

wherein the electrospray ionization probe is operated in positive ion mode, and wherein the organic solvent and base are capable of reducing a charge state of the ions.