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 selected from polyimides, polyketones, polycarbonates, polyesters, polyamides, polyethers, polyurethanes, polyfluorocarbons, polystyrenes, poly(acrylonitrile-butadiene-styrene), acrylate polymers, acrylic acid polymers, polyolefins, and copolymers thereof; and

(c) a hydrophobic coating substantially selectively covering the tip portion.

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 polyimides and polyketones.

4. 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 90°.

5. The electrospray device of claim 4 , wherein the contact angle is greater than 105°.

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

7. The electrospray device of claim 1 , wherein the hydrophobic coating is formed by plasma deposition of a reactant gas selected from fluorocarbons, hydrocarbons, gases that fragment to form hydrocarbons, gases that fragment to form fluorocarbons, fluorine-containing gases, and mixtures thereof.

8. 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 providing a hydrophobic surface that comprises a surface energy less than 20 mN/m;

(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 to produce ions from the sample stream.

9. The ion source of claim 8 , wherein the electrospray device further comprises a body portion, and the polymeric tip portion extends from the body portion.

10. The ion source of claim 9 , wherein the hydrophobic coating at least partly covers the polymeric tip portion, while the body portion is substantially uncovered.

11. The ion source of claim 8 , wherein the polymeric tip portion comprises a side surface, and the hydrophobic coating at least partly covers the side surface.

12. The ion source of claim 8 , wherein the polymeric tip portion comprises a terminus surface, and the hydrophobic coating at least partly covers the terminus surface.

13. The ion source of claim 8 , wherein the surface energy is less than 15 mN/m.

14. The ion source of claim 8 , wherein the hydrophobic coating is formed by plasma deposition of a reactant gas selected from fluorocarbons, hydrocarbons, gases that fragment to form hydrocarbons, gases that fragment to form fluorocarbons, fluorine-containing gases, and mixtures thereof.

15. A mass spectrometry system, comprising:

(a) an ion source comprising:

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

(1) a body portion;

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

(3) a coating at least partly covering the tip portion, while the body portion is substantially uncovered by the coating, the coating providing a hydrophobic surface and being formed by plasma deposition of a reactant gas selected from fluorocarbons, hydrocarbons, gases that fragment to form hydrocarbons, gases that fragment to form fluorocarbons, fluorine-containing gases, and mixtures thereof; 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.

16. The mass spectrometry system of claim 15 , wherein the coating comprises a surface energy that is less than 20 mN/m.