Polymeric solid supports for chromatography nanocolumns

• US 20060144770A1
• Filed: 02/06/2004
• Published: 07/06/2006
• Est. Priority Date: 02/07/2003
• Status: Active Grant

• Current Assignee: Waters Technologies Corporation (Waters Corporation)
• Original Assignee: Waters Investments Limited (Waters Corporation)
• Inventors: Granger, Jennifer H, Plumb, Robert
• Granted Patent: US 7,887,754 B2
• Time in Patent Office: Days
• US Class Current: 210/198.200
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 20/28026 Particles within, immobilised, dispersed, entrapped in or on a matrix, e.g. a resin
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28069 Pore volume, e.g. total pore volume, mesopore volume, micropore volume
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/281 Sorbents specially adapted for preparative, analytical or investigative chromatography
• CPC Class Codes: B01J 20/282 Porous sorbents ion exchange B01J39/00 - B01J41/00
• CPC Class Codes: B01J 20/283 based on silica
• CPC Class Codes: B01J 20/284 based on alumina
• CPC Class Codes: B01J 20/285 based on polymers
• CPC Class Codes: B01J 20/286 Phases chemically bonded to a substrate, e.g. to silica or to polymers
• CPC Class Codes: B01J 2220/54 Sorbents specially adapted for analytical or investigative chromatography
• CPC Class Codes: B01J 2220/84 Capillaries
• CPC Class Codes: G01N 30/603 retaining the stationary phase, e.g. Frits
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

Nanocolumn chromatography devices useful, e.g., in CEC and nanoLC are disclosed. An exemplary chromatography device of the invention includes a nanocolumn, e.g., a capillary, packed with a particulate stationary phase material and a solid support. The solid support, or in situ frit, is adjacent to and integral with the stationary phase material. An in situ frit of the invention may be a mixture of the stationary phase material and a polymeric network of cross-linked poly(diorganosiloxane), e.g., poly(dimethylsiloxane), which may optionally be sintered. The invention also provides methods of making and using such devices.

Claims

1. An in situ frit for immobilizing a stationary phase material in a chromatography nanocolumn comprising an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), wherein said particles are suspended in said network.

2. A medium for molecular separations comprising

a) a particulate stationary phase material;

and

b) an in situ frit adjacent to and integral with said stationary phase material, wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network.

3. A column chromatography device comprising

a) a nanocolumn having a cylindrical interior for accepting a stationary phase;

b) a particulate stationary phase material packed within said nanocolumn; and

c) an in situ frit within said nanocolumn, and adjacent to and integral with said stationary phase material, wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network.

5. The column chromatography device of claim 3, wherein said poly(diorganosiloxane) is a polymer having a repeat unit of the formula —

(—

R¹R²SiO—

)—

, wherein R¹ and R² are independently hydrogen, a C₁-C₁₈ aliphatic group, an aromatic group, or a cross-linking group.

6. The column chromatography device of claim 3, wherein said poly(diorganosiloxane) is a polymer having the formula (—

R¹R²SiO—

)_n, wherein R¹ and R² are independently hydrogen, a C₁-C₁₈ aliphatic group, an aromatic group, or a cross-linking group, and n represents the number of repeat units.

7. The column chromatography device of claim 6, wherein said cross-linking group is a hydrocarbon group containing a polymerizable alkenyl group or a polymerized product thereof.

8. The column chromatography device of claim 7, wherein said cross-linking group is a vinyl group or a styryl group or a polymerized product thereof.

9. The column chromatography device of claim 6, wherein said aliphatic group is a straight or branched-chain alkyl or cycloalkyl group.

10. The column chromatography device of claim 9, wherein said aliphatic group is a C₁-C₆ alkyl group.

11. The column chromatography device of claim 10, wherein said aliphatic group is a methyl, ethyl, n-propyl, isopropyl, butyl, sec-butyl, or tert-butyl group.

12. The column chromatography device of claim 3, wherein said poly(diorganosiloxane) is selected from poly(dimethylsiloxane) polymers.

13. The column chromatography device of claim 3, wherein said cross-linked poly(diorganosiloxane) is selected from the group consisting of cross-linked poly(dimethylsiloxane) polymers.

14. The column chromatography device of claim 3, wherein said cross-linked poly(diorganosiloxane) is produced by the reaction of a polymer reagent comprising vinyl-substituted dimethyl siloxane.

15. The column chromatography device of claim 14, wherein said vinyl-substituted dimethyl siloxane is dimethylvinyl-terminated dimethyl siloxane.

16. The column chromatography device of claim 14, wherein said reaction comprises a further polymer reagent selected from the group consisting of dimethyl siloxane, methylhydrogen siloxane, dimethylvinylated silica, trimethylated silica, tetramethyl tetravinyl cyclotetrasiloxane, and tetra(trimethylsiloxy) silane.

17. The column chromatography device of claim 16, wherein said dimethyl siloxane or methylhydrogen siloxane has an average molecular weight of about 10 Da to about 10,000.

18. The column chromatography device of claim 17, wherein said dimethyl siloxane or methylhydrogen siloxane has an average molecular weight of about 100 Da to about 1,000.

19. The column chromatography device of claim 14, wherein said vinyl-substituted dimethyl siloxane has an average molecular weight of about 500 Da to about 100,000 Da.

20. The column chromatography device of claim 19, wherein said vinyl-substituted dimethyl siloxane has an average molecular weight of about 10,000 Da to about 40,000 Da.

21. The column chromatography device of claim 3, wherein said mixture has been cured in situ by heating.

22. The column chromatography device of claim 3, wherein said mixture has been further immobilized by sintering.

23. The column chromatography device of claim 21, wherein said curing step comprises heating the mixture to a temperature of between about 25°

C. and about 150°

C. for a period of time ranging from about 1 hour to about 48 hours.

24. The column chromatography device of claim 3, wherein the particles of said stationary phase material have an average size/diameter of about 0.5 μ

m to about 10 μ

m.

25. The column chromatography device of claim 3, wherein said stationary phase material is porous.

26. The column chromatography device of claim 3, wherein said stationary phase material is non-porous.

27. The column chromatography device of claim 3, wherein said stationary phase material has an average pore diameter of about 70 Å

to about 300 Å

.

28. The column chromatography device of claim 3, wherein said stationary phase material has a specific surface area of about 170 m²/g to about 250 m²/g.

29. The column chromatography device of claim 3, wherein said stationary phase material has a specific pore volumes of about 0.2 cm³/g to about 1.5 cm³/g.

30. The column chromatography device of claim 3, wherein said particulate stationary phase material is alumina, silica, titanium oxide, zirconium oxide, a ceramic material, an organic polymer, or a mixture thereof.

31. The column chromatography device of claim 3, wherein said stationary phase material has been bonded with a surface modifier.

32. The column chromatography device of claim 31, wherein said surface modifier is selected from the group consisting of alkyl group, alkenyl group, alkynyl group, aryl group, cyano group, amino group, diol group, nitro group, ester group, or an alkyl or aryl group containing an embedded polar functionality.

33. The column chromatography device of claim 32, wherein said alkyl group is selected from the group consisting methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, sec-butyl, pentyl, isopentyl, hexyl, cyclohexyl, octyl, and octadecyl groups.

34. The column chromatography device of claim 3, wherein said stationary phase material is alkyl-bonded, phenyl-bonded, cyano-bonded, diol-bonded, or amino-bonded silica, or a mixture thereof.

35. The column chromatography device of claim 3, wherein said stationary phase material comprises porous inorganic/organic hybrid particles.

36. The column chromatography device of claim 3, wherein said stationary phase material comprises porous inorganic/organic hybrid particles having the formula SiO₂/(R²_pR⁴_qSiO_t)_n or SiO₂/[R⁶(R²_rSiO_t)_m]_n, wherein R² and R⁴ are independently C₁-C₁₈ aliphatic, styryl, vinyl, propanol, or aromatic groups, R⁶ is a substituted or unsubstituted C₁-C₁₈ alkylene, alkenylene, alkynylene or arylene group bridging two or more silicon atoms, p and q are 0, 1 or 2, provided that p+q=1 or 2, and that when p+q=1, t=1.5, and when p+q=2, t=1;

r is 0 or 1, provided that when r=0, t=1.5, and when r=1, t=1;

m is an integer greater than or equal to 2, and n is a number from 0.03 to 1.

37. The column chromatography device of claim 3, wherein said nanocolumn is a capillary.

38. The column chromatography device of claim 3, wherein the inner diameter of said nanocolumn is about 10 μ

m to about 1.0 mm.

39. The column chromatography device of claim 38, wherein said inner diameter is about 25 μ

M to about 320 μ

m.

40. The column chromatography device of claim 3, wherein said nanocolumn is made of fused silica, glass, stainless steel, a polymer, a ceramic, or a mixture thereof.

41. The column chromatography device of claim 3, wherein said in situ frit is about 0.25 mm to about 2.5 mm in length.

42. The column chromatography device of claim 41, wherein said in situ frit is about 0.5 mm to about 1.0 mm in length.

43. The column chromatography device of claim 3, wherein said in situ frit is located at an end of the packed bed within said nanocolumn.

44. The column chromatography device of claim 3, wherein said in situ frit is an outlet frit for a chromatography device.

45. The column chromatography device of claim 3, wherein said in situ frit is an inlet frit for a chromatography device.

46. The column chromatography device of claim 3, wherein said in situ frit capable of physically withstanding a pressure of at least about 1,000 psi applied to a liquid flowing through the stationary phase.

47. The column chromatography device of claim 3, wherein said in situ frit capable of physically withstanding chromatography pressures of at least about 10,000 psi applied to a liquid flowing through the stationary phase.

48. The column chromatography device of claim 3, wherein said in situ frit capable of physically withstanding chromatography pressures of at least about 20,000 psi applied to a liquid flowing through the stationary phase.

49. The column chromatography device of claim 3, wherein said in situ frit has a tailing factor less than or equal to 2.3.

106. A separations instrument comprising a column chromatography device according to claim 3.

107. The instrument of claim 106, wherein said instrument is a CE, nanoLC, or CEC instrument.

108. The instrument of claim 106, wherein said instrument comprises a pumping means for moving liquid through said column chromatography device, and a detecting means for analyzing the column chromatography device effluent.

110. A method of analyzing components of a mixture comprising a step of contacting said mixture with a column chromatography device according to claim 3.

111. A method of separating components of a mixture comprising a step of contacting said mixture with a column chromatography device according to claim 3.

112. The column chromatography device of claim 3, wherein said intimate mixture is a 10:

1 (w/w) composition of particles of stationary phase material and a polymeric network of cross-linked poly(diorganosiloxane) in a ratio of about 10;

1 to about 1000;

1 stationary phase material to polymer by weight.

113. The column chromatography device of claim 112, wherein said ratio is about 10:

1 to about 100;

1 stationary phase material to polymer by weight.

114. The column chromatography device of claim 3, wherein the particles of said stationary phase material are approximately spherical.

4. A chromatography device prepared by the steps of providing a nanocolumn having a cylindrical interior for accepting a stationary phase, and forming a stationary phase within said nanocolumn, wherein said stationary phase comprises

a) a particulate stationary phase material;

and

b) an in situ frit adjacent to and integral with said stationary phase material, wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network.

50. A method of making a chromatography device comprising the steps of

a) providing a nanocolumn having a cylindrical interior for accepting a stationary phase;

b) forming a stationary phase within said nanocolumn,

wherein said stationary phase comprises

i) a particulate stationary phase material; and

ii) an in situ frit adjacent to and integral with said stationary phase material,

wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network;

c) curing the stationary phase within said nanocolumn; and

d) optionally sintering the stationary phase within said nanocolumn.

52. The method of claim 50, wherein said step of forming a stationary phase comprises the steps of

a) preparing a mixture of said stationary phase material, a solvent, and synthetic precursors of cross-linked poly(diorganosiloxane);

b) introducing said mixture prepared in step (a) into an end of said nanocolumn;

c) allowing the solvent to evaporate at room temperature;

d) curing the dried mixture by heating the nanocolumn and the mixture therein to a temperature of between about 70°

C. to about 150°

C. for a period of time ranging from about 0.5 hours to about 3 hours to thereby produce an in situ frit; and

e) optionally sintering the in situ frit by heating the nanocolumn and the in situ frit therein to a temperature of between about 250°

C. and about 350°

C. for a period of time ranging from about 5 seconds to about 30 second.

53. The method of claim 50, wherein said curing step comprises heating the mixture to a temperature of between about 20°

C. to about 40°

C. for a period of time ranging from about 5 hours to about 35 hours, followed directly by heating the mixture to a temperature of between about 70°

C. to about 150°

C. for a period of time ranging from about 0.5 hours to about 3 hours.

54. The method of claim 50, wherein said curing step comprises heating the mixture to room temperature for a period of about one day, followed by heating the mixture to a temperature of about 110°

C. for a period of time of about 2 hours.

55. The method of claim 50, wherein said sintering step comprises heating the mixture to a temperature of between about 250°

C. and about 350°

C. for a period of time ranging from about 5 seconds to about 30 seconds.

56. The method of claim 55, wherein the diameter of said in situ frit is greater than about 30 μ

m.

57. The method of claim 50, wherein said sintering step comprises heating the mixture to a temperature of about 300°

C. for a period of time of about 15 seconds.

58. The method of claim 55, wherein the diameter of said in situ frit is greater than about 30 μ

m.

59. The method of claim 50, wherein said poly(diorganosiloxane) is a polymer having a repeat unit of the formula —

(—

R¹R²SiO—

)—

, wherein R¹ and R² are independently hydrogen, a C₁-C₁₈ aliphatic group, an aromatic group, or a cross-linking group.

60. The method of claim 50, wherein said poly(diorganosiloxane) is a polymer having the formula (—

R¹R²SiO—

)_n, wherein R¹ and R² are independently hydrogen, a C₁-C₁₈ aliphatic group, an aromatic group, or a cross-linking group, and n represents the number of repeat units.

61. The method of claim 59, wherein said cross-linking group is a hydrocarbon group containing a polymerizable alkenyl group or a polymerized product thereof.

62. The method of claim 61, wherein said cross-linking group is a vinyl group or a styryl group or a polymerized product thereof.

63. The method of claim 60, wherein said aliphatic group is a straight or branched-chain alkyl or cycloalkyl group.

64. The method of claim 60, wherein said aliphatic group is a C₁-C₆ alkyl group.

65. The method of claim 64, wherein said aliphatic group is a methyl, ethyl, n-propyl, isopropyl, butyl, sec-butyl, or tert-butyl group.

66. The method of claim 50, wherein said poly(diorganosiloxane) is selected from poly(dimethylsiloxane) polymers.

67. The method of claim 50, wherein said cross-linked poly(diorganosiloxane) is selected from the group consisting of cross-linked poly(dimethylsiloxane) polymers.

68. The method of claim 50, wherein said cross-linked poly(diorganosiloxane) is produced by the reaction of a polymer reagent comprising vinyl-substituted dimethyl siloxane.

69. The method of claim 68, wherein said vinyl-substituted dimethyl siloxane is dimethylvinyl-terminated dimethyl siloxane.

70. The method of claim 68, wherein said reaction comprises a further polymer reagent selected from the group consisting of dimethyl siloxane, methylhydrogen siloxane, dimethylvinylated silica, trimethylated silica, tetramethyl tetravinyl cyclotetrasiloxane, and tetra(trimethylsiloxy) silane.

71. The method of claim 70, wherein said dimethyl siloxane or methylhydrogen siloxane has an average molecular weight of about 10 Da to about 10,000.

72. The method of claim 71, wherein said dimethyl siloxane or methylhydrogen siloxane has an average molecular weight of about 100 Da to about 1,000.

73. The method of claim 68, wherein said vinyl-substituted dimethyl siloxane has an average molecular weight of about 500 Da to about 100,000 Da.

74. The method of claim 73, wherein said vinyl-substituted dimethyl siloxane has an average molecular weight of about 10,000 Da to about 40,000 Da.

75. The method of claim 50, wherein said mixture has been cured in situ by heating.

76. The method of claim 50, wherein said mixture has been further immobilized by sintering.

77. The method of claim 50, wherein said curing step comprises heating the mixture to a temperature of between about 25°

C. and about 150°

C. for a period of time ranging from about 1 hour to about 48 hours.

78. The method of claim 50, wherein the particles of said stationary phase material have an average size/diameter of about 0.5 μ

m to about 10 μ

m.

79. The method of claim 50, wherein said stationary phase material is porous.

80. The method of claim 50, wherein said stationary phase material is non-porous.

81. The method of claim 50, wherein said stationary phase material has an average pore diameter of about 70 Å

to about 300 Å

.

82. The method of claim 50, wherein said stationary phase material has a specific surface area of about 170 m²/g to about 250 m²/g.

83. The method of claim 50, wherein said stationary phase material has a specific pore volumes of about 0.2 cm³/g to about 1.5 cm³/g.

84. The method of claim 50, wherein the particulate stationary phase material is alumina, silica, titanium oxide, zirconium oxide, a ceramic material, an organic polymer, or a mixture thereof.

85. The method of claim 50, wherein said stationary phase material has been bonded with a surface modifier.

86. The method of claim 85, wherein said surface modifier is selected from the group consisting of alkyl group, alkenyl group, alkynyl group, aryl group, cyano group, amino group, diol group, nitro group, ester group, or an alkyl or aryl group containing an embedded polar functionality.

87. The method of claim 86, wherein said alkyl group is selected from the group consisting methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, sec-butyl, pentyl, isopentyl, hexyl, cyclohexyl, octyl, and octadecyl groups.

88. The method of claim 50, wherein said stationary phase material is alkyl-bonded, phenyl-bonded, cyano-bonded, diol-bonded, or amino-bonded silica, or a mixture thereof.

89. The method of claim 50, wherein said stationary phase material comprises porous inorganic/organic hybrid particles.

90. The method of claim 50, wherein said stationary phase material comprises porous inorganic/organic hybrid particles having the formula SiO₂/(R²_pR⁴_qSiO_t)_n or SiO₂/[R⁶(R²_rSiO_t)_m]_n, wherein R² and R⁴ are independently C₁-C₁₈ aliphatic, styryl, vinyl, propanol, or aromatic groups, R⁶is a substituted or unsubstituted C₁-C₁₈ alkylene, alkenylene, alkynylene or arylene group bridging two or more silicon atoms, p and q are 0, 1 or 2, provided that p+q=1 or 2, and that when p+q=1, t=1.5, and when p+q=2, t=1;

r is 0 or 1, provided that when r=0, t=1.5, and when r=1, t=1;

m is an integer greater than or equal to 2, and n is a number from 0.03 to 1.

91. The method of claim 50, wherein said nanocolumn is a capillary.

92. The method of claim 50, wherein the inner diameter of said nanocolumn is about 10 μ

m to about 1.0 mm.

93. The method of claim 92, wherein said inner diameter is about 25 μ

M to about 320 μ

m.

94. The method of claim 50, wherein said nanocolumn is made of fused silica, glass, stainless steel, a polymer, a ceramic, or a mixture thereof.

95. The method of claim 50, wherein said in situ frit is about 0.25 mm to about 2.5 mm in length.

96. The method of claim 95, wherein said frit is about 0.5 mm to about 1.0 mm in length.

97. The method of claim 50, wherein said in situ frit is located at an end of the packed bed within said nanocolumn.

98. The method of claim 50, wherein said in situ frit is an outlet frit for a chromatography device.

99. The method of claim 50, wherein said in situ frit is an inlet frit for a chromatography device.

100. The method of claim 50, wherein said in situ frit capable of physically withstanding a pressure of at least about 1,000 psi applied to a liquid flowing through the stationary phase.

101. The method of claim 50, wherein said in situ frit capable of physically withstanding chromatography pressures of at least about 10,000 psi applied to a liquid flowing through the stationary phase.

102. The method of claim 50, wherein said in situ frit capable of physically withstanding chromatography pressures of at least about 20,000 psi applied to a liquid flowing through the stationary phase.

103. The method of claim 50, wherein said in situ frit has a tailing factor less than or equal to 2.3.

115. A method of claim 50, wherein said intimate mixture is a 10:

1 (w/w) composition of particles of stationary phase material and a polymeric network of cross-linked poly(diorganosiloxane) in a ratio of about 10;

1 to about 1000;

1 stationary phase material to polymer by weight.

116. The method of claim 115, wherein said ratio is about 10:

1 to about 100;

1 stationary phase material to polymer by weight.

117. The method of claim 50, wherein the particles of said stationary phase material are approximately spherical.

51. A method of making a chromatography device comprising the steps of

a) preparing a mixture of a stationary phase material, a solvent, and polymer reagents that produce cross-linked poly(diorganosiloxane);

b) introducing said mixture prepared in step (a) into an end of said nanocolumn;

c) allowing the solvent to evaporate at room temperature;

d) curing the dried mixture by heating the nanocolumn and the mixture therein to a temperature of between about 70°

C. to about 150°

C. for a period of time ranging from about 0.5 hours to about 3 hours to thereby produce an in situ frit; and

e) optionally sintering the in situ frit by heating the nanocolumn and the in situ frit therein to a temperature of between about 250°

C. and about 350°

C. for a period of time ranging from about 5 seconds to about 30 second.

118. A method of claim 51, wherein said mixture prepared in step (a) contains sufficient amounts of stationary phase material, solvent, and polymer reagents to yield after curing in step (d) a 10:

1 (w/w) composition of particles of stationary phase material and a polymeric network of cross-linked poly(diorganosiloxane) in a ratio of about 10;

1 to about 1000;

1 stationary phase material to polymer by weight.

119. The method of claim 118, wherein said ratio is about 10:

1 to about 100;

1 stationary phase material to polymer by weight.

120. The method of claim 51, wherein the particles of said stationary phase material are approximately spherical.

104. A separations instrument comprising a (i) column chromatography device and at least one component selected from a (ii) detecting means, an (iii) introducing means, or an (iv) accepting means, wherein

(i) said column chromatography device comprises

a) a nanocolumn having a cylindrical interior for accepting a stationary phase,

b) a particulate stationary phase material packed within said nanocolumn, and

c) an in situ frit within said nanocolumn, and adjacent to and integral with said stationary phase material, wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network;

(ii) said detecting means is operatively connected to said nanocolumn and is capable of measuring physicochemical properties; and

(iii) said introducing means is operatively connected to said nanocolumn and is capable of conducting a liquid into said nanocolumn; and

(iv) said accepting means is capable of holding said nanocolumn in a configuration in which the nanocolumn is operatively connected to either a detecting means or an introducing means.

105. A separations instrument comprising a column chromatography device comprising

a) a nanocolumn having a cylindrical interior for accepting a stationary phase;

b) a particulate stationary phase material packed within said nanocolumn; and

c) an in situ frit within said nanocolumn, and adjacent to and integral with said stationary phase material, wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network.

109. An analytical method of separating components of a mixture comprising a step of contacting said mixture with a column chromatography device comprising

a) a nanocolumn having a cylindrical interior for accepting a stationary phase;

b) a particulate stationary phase material packed within said nanocolumn; and

c) an in situ frit within said nanocolumn, and adjacent to and integral with said stationary phase material, wherein said in situ frit comprises an intimate mixture of particles comprising a stationary phase material and a polymeric network comprising cross-linked poly(diorganosiloxane), and wherein said particles are suspended in said network.