Electrospray devices for mass spectrometry

1. An electrospray device for a mass spectrometry system, comprising:

(a) a body portion;

(b) a tip portion extending from the body portion, the tip portion comprising a polymeric material; and

(c) a hydrophobic coating substantially selectively covering the tip portion, the hydrophobic coating being electrically nonconductive.

2. The electrospray device of claim 1 , wherein the tip portion is formed integrally with the body portion.

3. The electrospray device of claim 1 , wherein the polymeric material is selected from the group consisting of polyimides and polyketones.

4. The electrospray device of claim 1 , wherein the hydrophobic coating comprises a resistivity that is greater than 0.001 Ω·cm.

5. The electrospray device of claim 4 , wherein the resistivity is greater than 0.01 Ω·cm.

6. The electrospray device of claim 1 , wherein the hydrophobic coating provides a hydrophobic surface, and the hydrophobic surface exhibits a contact angle with respect to water that is greater than 100°.

7. The electrospray device of claim 6 , wherein the contact angle is greater than 105°.

8. The electrospray device of claim 1 , wherein the hydrophobic coating at least partly covers the tip portion, while the body portion is substantially uncovered.

9. The electrospray device of claim 1 , wherein the hydrophobic coating is formed by plasma deposition of at least one of a fluorocarbon plasma and a hydrocarbon plasma.

10. An ion source for a mass spectrometry system, comprising:

(a) an electrospray device comprising:

(i) a polymeric tip portion, the polymeric tip portion being elongated and defining a conduit configured to pass a sample stream; and

(ii) a hydrophobic coating at least partly covering the polymeric tip portion, the hydrophobic coating comprising a resistivity that is greater than 0.001 Ω·cm;

(b) an electrode positioned adjacent to the electrospray device; and

(c) a power source in electrical connection with the electrospray device and the electrode, the power source being configured to apply a voltage between the electrospray device and the electrode, such that ions are produced from the sample stream and are directed towards the electrode.

11. The ion source of claim 10 , wherein the electrospray device further comprises a body portion, and the polymeric tip portion extends from the body portion.

12. The ion source of claim 11 , wherein the hydrophobic coating at least partly covers the polymeric tip portion, while the body portion is substantially uncovered.

13. The ion source of claim 10 , wherein the polymeric tip portion comprises a side surface, and the hydrophobic coating at least partly covers the side surface.

14. The ion source of claim 10 , wherein the polymeric tip portion comprises a terminus surface, and the hydrophobic coating at least partly covers the terminus surface.

15. The ion source of claim 10 , wherein the hydrophobic coating provides a hydrophobic surface, and the hydrophobic surface comprises a surface energy that is less than 20 mN/m.

16. The ion source of claim 15 , wherein the surface energy is less than 15 mN/m.

17. The ion source of claim 10 , wherein the hydrophobic coating is formed by plasma deposition of at least one of a fluorocarbon plasma and a hydrocarbon plasma.

18. A mass spectrometry system, comprising:

(a) an ion source comprising:

(i) an electrospray device configured to pass a sample stream, the electrospray device comprising:

(a) a body portion;

(b) a tip portion extending from the body portion, the tip portion comprising a polymeric material; and

(c) a coating at least partly covering the tip portion, while the body portion is substantially uncovered, the coating being electrically nonconductive and providing a hydrophobic surface; and

(ii) an electrode positioned with respect to the electrospray device, wherein, when a voltage between the electrospray device and the electrode is applied, ions are produced from the sample stream and are directed towards the electrode; and

(b) a detector positioned with respect to the ion source to detect the ions.

19. The mass spectrometry system of claim 18 , wherein the coating comprises a resistivity that is greater than 0.001 Ω·cm.

20. The mass spectrometry system of claim 18 , wherein the coating is formed by plasma deposition of a fluorocarbon plasma.