Temperature-assisted on-column focusing

Patent metadata

Field	Value
Publication number	US-2016206971-A1
Application number	US-201614996104-A
Country	US
Kind code	A1
Filing date	Jan 14, 2016
Priority date	Jan 16, 2015
Publication date	Jul 21, 2016
Grant date	—

Abstract

A method of comprising:
introducing a sample volume into an inlet end of a liquid chromatography column, wherein the liquid chromatography column includes a focusing segment proximal to the inlet end of the liquid chromatography column and a separation segment proximal to an elute outlet of the liquid chromatography column; maintaining only the focusing segment at a first temperature as the sample is introduced into the focusing segment; and subsequently heating the focusing segment to a second temperature that is higher than the first temperature after the entire sample volume has been introduced into the focusing segment.

First claim

What is claimed is:

1 . A method comprising:
introducing a sample volume into an inlet end of a liquid chromatography column, wherein the liquid chromatography column includes a focusing segment proximal to the inlet end of the liquid chromatography column and a separation segment proximal to an elute outlet of the liquid chromatography column; maintaining only the focusing segment at a first temperature as the sample is introduced into the focusing segment; and subsequently heating the focusing segment to a second temperature that is higher than the first temperature after the entire sample volume has been introduced into the focusing segment.

2 . The method of claim 1 , further comprising heating the separation segment while cooling the focusing segment.

3 . The method of claim 1 , wherein the second temperature is at least 20° C. greater than the first temperature, more particularly at least 30° C. greater than the first temperature, and most particularly at least 50° C. greater than the first temperature.

4 . The method of claim 1 , wherein maintaining the focusing segment at a first temperature comprises cooling the focusing segment for less than 1000 seconds, more particularly 60 seconds or less, and most particularly about 20 seconds or less.

5 . The method of claim 1 , wherein the separation segment is not cooled.

6 . The method of claim 1 , wherein the liquid chromatography column is a capillary liquid chromatography column.

7 . The method of claim 1 , wherein the total sample volume is at least 50 volume %, more particularly at least 100 volume %, of the total liquid chromatography column volume.

8 . The method of claim 1 , wherein separation of the sample volume is completed in less than three minutes.

9 . The method of claim 1 , wherein the focusing segment contains particles having an average particle diameter that is greater than the average particle diameter of particles contained in the separation segment.

10 . The method of claim 1 , further comprising introducing the sample volume into an inlet segment that is adjacent to the inlet end of the liquid chromatography column prior to introducing the sample volume into the focusing segment.

11 . The method of claim 10 , wherein the inlet segment contains a sample injection element and noninteracting, nonporous silica spheres.

12 . The method of claim 1 , wherein the focusing segment has a length that is 1 to 50 percent, more particularly 3 to 35 percent, and most particularly 5 to 20 percent, of the total length of the sum of the focusing segment length and the separation segment length.

13 . The method of claim 1 , wherein the sample is associated with a mobile phase and the method further comprises applying a constant pressure to the mobile phase throughout a retention time period of the sample volume in the focusing segment and the separation segment.

14 . The method of claim 1 , further comprising diluting the sample with a weak solvent.

15 . The method of claim 1 , wherein the first temperature is ≦30° C., particularly 30° C. to −20° C., more particularly between 20 to −5° C., and most particularly between 10 to 0° C.

16 . A device comprising:
a liquid chromatography column having a longitudinal axial length and including a sample introduction inlet, an elute outlet, a longitudinally-extending focusing segment proximal to the inlet end of the liquid chromatography column, and a longitudinally-extending separation segment proximal to the elute outlet end of the liquid chromatography column, wherein the focusing segment is longitudinally axially adjacent to the separation segment within the liquid chromatography column; and at least one Peltier thermoelectric cooling element aligned along the focusing segment.

17 . The device of claim 16 , wherein the focusing segment has a longitudinally-extending length that is 1 to 50 percent, more particularly 3 to 35 percent, and most particularly 5 to 20 percent, of the total length of the sum of the focusing segment longitudinally-extending length and the separation segment longitudinally-extending length.

18 . The device of claim 16 , wherein the liquid chromatography column is a capillary liquid chromatography column.

19 . The device of claim 16 , wherein the focusing segment contains particles having an average particle diameter that is larger than the average particle diameter of particles contained in the separation segment.

20 . The device of claim 16 , further comprising an inlet segment longitudinally axially adjacent to the inlet end of the liquid chromatography.

21 . The device of claim 20 , wherein the inlet segment contains a sample injection element and noninteracting, nonporous silica spheres.

22 . The method of claim 1 , wherein the liquid chromatography column includes more than one focusing segment, and the method comprises:
maintaining a first focusing segment and at least one second focusing segment at a first temperature as the sample is introduced into the first focusing segment; and subsequently heating the first focusing segment to a second temperature that is higher than the first temperature while maintaining the at least one second focusing segment at the first temperature; and subsequently heating the at least one second focusing segment to a third temperature that is higher than the first temperature.

23 . The device of claim 16 , wherein the device includes at least two focusing segments.

24 . A device comprising:
an elongated body defining an internal annular elongated column having a sample introduction inlet, a sample outlet, and at least one longitudinally-extending focusing segment; a thermal sheet contiguous with an outer surface of the body; at least one Peltier thermoelectric cooling element aligned along the at least one focusing segment and contiguous with an outer surface of the thermal sheet; and a heat sink contiguous with an outer surface of the Peltier thermoelectric cooling element.

25 . A device comprising:
a precolumn having a longitudinal axial length and comprising a sample introduction inlet, an elute outlet, at least one longitudinally-extending focusing segment, and at least one Peltier thermoelectric cooling element aligned along the focusing segment; and a liquid chromatography column coupled to the elute outlet the precolumn, wherein the liquid chromatography column includes a longitudinally-extending separation segment.

26 . A method for modifying a liquid chromatography column comprising coupling to a sample inlet of the liquid chromatography column a precolumn having a longitudinal axial length and comprising a sample introduction inlet, an elute outlet, at least one longitudinally-extending focusing segment, and at least one Peltier thermoelectric cooling element aligned along the focusing segment, wherein the sample inlet of the liquid chromatography column is coupled to the elute outlet of the precolumn.

Assignees

• Univ Pittsburgh

Inventors

• Weber Stephen
• Groskreutz Stephen Robert
• Horner Anthony Robert
• Wilson Rachael-Anh Elizabeth

Classifications

• G01N2030/027

  Liquid chromatography · CPC title

• B01D15/325

  Reversed phase · CPC title

• B01D15/305

  Hydrophilic interaction chromatography [HILIC] · CPC title

• B01D15/1871

  placed in series · CPC title

• B01D15/1864

  using two or more columns · CPC title