Textured needle for improved piercing performance in liquid chromatography applications

Patent metadata

Field	Value
Publication number	US-10859541-B2
Application number	US-201916292857-A
Country	US
Kind code	B2
Filing date	Mar 5, 2019
Priority date	Mar 6, 2018
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A needle for aspirating a sample from a sample source and injecting the sample into a liquid chromatography system, the needle including a needle body having a rough textured surface finish for at least a portion of the needle body, wherein the rough textured surface finish reduces a coefficient of friction of the needle body, is provided. Furthermore, an associated method is also provided.

First claim

What is claimed is:

1. A needle comprising:
a needle body including a tip and a conical section adjacent to the tip, the conical section having a textured surface that is offset from the tip of the needle body, the tip having a non-textured, smooth surface;
wherein the needle is configured to aspirate a sample from a sample source and inject the sample into a liquid chromatography system.

2. The needle of claim 1 , wherein the textured surface reduces a coefficient of friction of the needle body and the non-textured, smooth surface of the tip maintains a liquid tight seal between the tip of the needle body and an injection seat when the needle injects the sample into an analytic flow path of the liquid chromatography system.

3. The needle of claim 2 , wherein the textured surface is offset from the tip of the needle body at least 0.010 inches.

4. The needle of claim 1 , wherein the textured surface is a rough textured surface finish having a surface roughness Ra greater than 15μ inch.

5. The needle of claim 1 , wherein the textured surface reduces the coefficient of friction of the needle body to avoid a seal material covering the sample source from clinging to the needle body as the needle enters and exits the sample source.

6. The needle of claim 1 , wherein the needle body is comprised of metal or a metal alloy.

7. The needle of claim 1 , wherein the textured surface is formed by bead blasting the needle body.

8. The needle of claim 1 , further comprising: an inner bore providing a fluidic pathway of the sample through the needle body, and an opposing attachment end for attaching to a component of an autosampler of the liquid chromatography system.

9. The needle of claim 8 , wherein the inner bore has a max diameter of 0.01 inches.

10. The needle of claim 1 , wherein a roughness Ra of the textured surface is between 15μ inch and 30μ inch.

11. The needle of claim 1 , wherein the textured surface extends at least 2 inches from the non-textured, smooth surface finish of the tip of the needle body, along an exterior surface of the needle body.

12. The needle of claim 1 , wherein the non-textured, smooth surface has a higher coefficient of friction than the textured surface.

13. The needle of claim 1 , wherein a circumference of the tip gradually reduces towards an end face of the tip.

14. The needle of claim 1 , wherein an end face of the tip is perpendicular to a longitudinal axis of the needle body.

15. An autosampler of a liquid chromatography system, comprising:
an injection valve for injecting a sample into an analytic flowpath of the liquid chromatography system;
a sample compartment, the sample compartment configured to receive at least one sample source having a seal; and
a sample needle fluidically connected to the injection valve, the sample needle configured to aspirate the sample from the at least one sample source by piercing the seal of the at least one sample source, and then injecting the sample into the analytic flowpath of the liquid chromatography system;
wherein the sample needle has a conical section with a textured exterior surface that is offset from a tip of the needle body, the tip having a non-textured, smooth surface.

16. The autosampler of claim 15 wherein the textured exterior surface reduces a coefficient of friction due to the textured exterior surface, which hinders stretching and sleeving of the seal as the sample needle enters and exits the at least one sample source.

17. The autosampler of claim 15 , wherein the non-textured, smooth surface of the tip maintains a liquid tight seal between the tip of the sample needle and an injection seat when the sample needle injects the sample into the analytic flow path of the liquid chromatography system.

18. A method of improving a piercing performance of a needle in a liquid chromatography system, the method comprising:
reducing a coefficient of friction of the needle by forming a rough textured surface region on an exterior surface of a conical section of the needle, such that when the needle pierces a seal of a sample source, the seal does not cling to the rough textured surface region of the needle as a result of the reduced coefficient of friction, wherein the rough textured surface region is offset from a tip portion of the needle having a non-textured, smooth surface;
wherein the needle is configured to aspirate a sample from the sample source and injects the sample into the liquid chromatography system.

19. The method of claim 18 , wherein the rough textured surface region has a roughness Ra between 15μ inch and 30μ inch.

Assignees

• Waters Technologies Corp

Inventors

• Kelley Scott
• Osswald Peter
• Solow Rose
• Auclair John M

Classifications

• B23K26/282

  of tube sections · CPC title

• G01N30/24 Primary

  Automatic injection systems · CPC title

• B29C66/30322

  in the form of rugosity · CPC title

• B23K26/3584

  Increasing rugosity, i.e. roughening · CPC title

• B23K2101/20

  Tools · CPC title