Separation device with integral guard column

• US 20060186029A1
• Filed: 01/11/2006
• Published: 08/24/2006
• Est. Priority Date: 07/14/2003
• Status: Active Grant

• Current Assignee: Waters Technologies Corporation (Waters Corporation)
• Original Assignee: Waters Investments Limited (Waters Corporation)
• Inventors: Granger, Jennifer Harnisch, Plumb, Robert
• Granted Patent: US 8,685,239 B2
• Time in Patent Office: Days
• US Class Current: 210/198.200
• CPC Class Codes: B01D 15/22 relating to the construction of the column
• CPC Class Codes: G01N 2030/085 using absorbing precolumn
• CPC Class Codes: G01N 30/60 Construction of the column
• CPC Class Codes: G01N 30/6039 in series
• CPC Class Codes: G01N 30/6065 with varying cross section
• CPC Class Codes: G01N 30/6069 with compartments or bed substructure

Abstract

A separation device is formed of a first tube with a cylindrical wall enclosing a chamber having a first diameter, where the device has a first end for discharging a fluid and a second end for receiving a fluid. At least two stationary phase medias are packed into the chamber with separating frits between the medias. At least one end frit element, secured to an inner surface of the first tube contains the media in its section of the chamber and allows the beds formed of the media to be formed and packed. When the separation device so constructed forms a nanocolumn with a guard bed, the guard bed may be cleaved from the separation device extending the useful life of the nanocolumn. When the separation device so constructed comprises two analytical sections, and a plurality of guard beds, complex analysis may be performed on a column having an extended useful life.

Claims

1. A separation device comprising:

a first tube having a cylindrical wall having an inner surface defining a chamber having a first diameter, an exterior surface defining a second diameter, a first end and a second end, said first end for discharging a fluid and said second end for receiving a fluid, said chamber having a first section and at least one second section;

a first media contained within said first section;

a second media contained within said at least one second section;

at least one separating frit element, said separating frit element disposed within said first tube between said sections of said chamber, for separating said medias; and

at least one end frit element, said end frit element secured to said inner surface of said first tube and containing at least one media selected from the group consisting of said first media in said first section and said second media in a last second section.

2. The separation device of claim 1 wherein said at least one end frit element has an end aligned with one end of said first tube, said one end selected from the group consisting of said first end and said second end, to provide minimal dead space associated with bandspreading.

3. The separation device of claim 1 wherein at least one frit element selected from said separating frit element and said end frit element is a second tube having a second cylindrical wall having a second inner surface defining a cavity with a third diameter, a second exterior surface defining a fourth diameter, a third end and a fourth end, said fourth diameter cooperating with said first diameter to contain at least one media.

4. The separation device of claim 3 wherein said fourth diameter is slightly smaller than said first diameter.

5. The separation device of claim 4 wherein a difference between said fourth diameter and said first diameter is between approximately 5 and 20 μ

m.

6. The separation device of claim 4 wherein a difference between said fourth diameter and said first diameter is approximately 10 μ

m.

7. The separation device of claim 3 wherein said second tube used as a separating frit has a length that is between approximately 0.5and 3 cm.

8. The separation device of claim 3 wherein said second tube used as a separating frit has a length of approximately 1 cm.

9. The separation device of claim 3 wherein an end selected from said third and said fourth ends is oriented perpendicular to a length of said second tube.

10. The separation device of claim 3 wherein said third diameter is between approximately 10% and 30% of said first diameter.

11. The separation device of claim 3 wherein said at least one frit element is an end frit element disposed in said first end for discharging fluid, said end frit element forming a transfer tube for transporting said fluid from said separating device.

12. The separation device of claim 1 wherein said first diameter is between approximately 25 μ

m and 180 μ

m.

13. The separation device of claim 12 wherein said first tube is formed of fused silica.

14. The separation device of claim 12 wherein said first diameter is between 70 μ

m and 110 μ

m.

15. The separating device of claim 12 wherein said end frit element is formed as an immobilized stationary phase comprising a intimate mixture of particles comprising a stationary phase material and a polymeric network.

16. The separating device of claim 15 wherein said polymeric network is a cross-linked poly(diorganosiloxane) and wherein said articles are suspended in said poly(diorganosiloxane).

17. The separating device of claim 15 wherein said poly(diorganosiloxane) is polydimethelseloxane (PDMS).

18. The separating device of claim 12 wherein said device may be cleaved at a boundary between said separating frit and said media disposed toward said second end of said first tube.

19. The separating device of claim 18 further comprising at least one marking on said outer surface of said first tube indicating a location of said boundary between said separating frit and said media disposed toward said second end of said first tube.

20. The separating device of claim 1 wherein said first media is formed as a first analytical bed and said second media is formed as a second analytical bed.

21. The separating device of claim 1 further comprising:

at least one additional second section in said chamber, said additional second section for containing a third media; and

at least one additional separating frit element, said at least one additional separating frit element disposed between said second media in said second section and said third media in said additional second section.

22. The separating device of claim 21 wherein said first media is formed as a first analytical bed, said second media is formed as a second analytical bed and said third media is formed as a guard bed.

23. The separating device of claim 21 wherein said first media is formed as a first analytical bed, said second media is formed as a guard bed, and said third media is formed as a guard bed.

24. The separating device of claim 23 wherein said media is selected from the group consisting of said second media formed as a guard bed and said third media formed as a guard bed are composed of a stationary phase selected from the set of ion exchange phase, reversed phase, size exclusion phase and affinity phase.

25. The separating device of claim 21 wherein said at least one additional second section containing said third media is formed as a guard bed and the number of additional second sections is between one and nine.

26. The separating device of claim 21 wherein said media selected from the group consisting of said first media formed as an analytical bed and said second media formed as an analytical bed are composed of a stationary phase selected from the set of ion exchange phase, reversed phase, size exclusion phase and affinity phase.

27. The separating device of claim 1 wherein said at least one separating frit is composed of a layer of glass microspheres.

28. The separating column of claim 27 wherein a thickness of said layer of glass microspheres is between approximately 250 and 500 μ

m.

29. The separating column of claim 27 wherein a thickness of said layer of glass microspheres is approximately 250 μ

m.

30. The separating column of claim 27 wherein a diameter of said glass microspheres is between approximately 3.5 and 5.0 μ

m.

31. The separating column of claim 27 wherein a diameter of said glass microspheres is approximately 5.0 μ

m.

32. The separating device of claim 1 wherein said first media is formed as a first analytical bed and said second media is formed as a guard bed.

Methods

33. A method of making a separation device in a first tube having a cylindrical wall having an inner surface defining a chamber first diameter, an exterior surface defining a second diameter, a first end for discharging a fluid and a second end for receiving a fluid, said chamber having a first section and at least one second section comprising:

a. securing a first end frit in an end of said first tube;

b. loading and packing an analytical media behind said first end frit in said first section forming a packed analytical bed;

c. placing a separating frit behind said packed analytical bed in said first tube; and

d. loading and packing a second analytical media behind said separating frit in said second section forming a second packed analytical bed.

34. The method of claim 33 further comprising securing a second end frit in said first tube behind said second packed analytical bed.

35. The method of making a separation device of claim 33 wherein said first end frit is a length of a second tube having a second cylindrical wall having a second inner surface defining a cavity with a third diameter, a second exterior surface defining a fourth diameter.

36. The method of making a separation device of claim 35 wherein said first end frit and/or said second end frit is secured in said first tube by gluing.

37. The method of making a separation device of claim 33 wherein said separation frit is a length of a second tube having a second cylindrical wall having a second inner surface defining a cavity with a third diameter, a second exterior surface defining a fourth diameter.

38. The method of making a separation device of claim 33 further comprising repeating steps c. and d. up to four additional times.

39. The method of making a separation device of claim 33 wherein said first end frit is formed as an immobilized stationary phase comprising a mixture of particles comprising a stationary phase material and a polymeric network in an end of said first tube.

40. The method of making a separation device of claim 33 wherein said separation frit is formed as a layer of glass microspheres.

41. A method of using a separation device to analyze samples, said samples comprising at least one component which can be separated from another component, said method comprising:

a. providing a separating device comprising;

a first tube having a cylindrical wall having an inner surface defining a chamber having a first diameter, an exterior surface defining a second diameter, a first end and a second end, said first end for discharging a fluid and said second end for receiving a fluid, said chamber having a first section and at least one second section;

a first media contained within said first section;

a second media contained within said at least one second section, said second media contained within a second section termed a guard column;

at least one separating frit element, said separating frit element disposed within said first tube between said sections of said chamber, for separating said medias; and

at least one end frit element, said end frit element secured to said inner surface of said first tube and containing at least one media selected from the group consisting of said first media in said first section and said second media in a last second section;

b. flowing a sequence of samples through said separating device to determine a set of components in each sample until the resolution of the peaks is degraded;

c. removing a guard column by cleaving said first tube at an edge of one of said separating frits, said edge disposed toward said second end of said first tube, creating a shortened separation device; and

d. flowing a sequence of samples through said shortened separating device to determine a set of components in each sample until the resolution of the peaks is degraded.

42. The method of using a separation device of claim 41 wherein degraded resolution is when the column peak width is increased by 20% from an original value.