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WO2002094410A1 - Colonne capillaire de separation/extraction a dendrites de sol-gel - Google Patents

Colonne capillaire de separation/extraction a dendrites de sol-gel Download PDF

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Publication number
WO2002094410A1
WO2002094410A1 PCT/US2002/015818 US0215818W WO02094410A1 WO 2002094410 A1 WO2002094410 A1 WO 2002094410A1 US 0215818 W US0215818 W US 0215818W WO 02094410 A1 WO02094410 A1 WO 02094410A1
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Prior art keywords
sol
gel
moieties
derivatives
group
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Inventor
Abdul Malik
Abuzar Kabir
George R. Newkome
Kyung Soo Yoo
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University of South Florida
University of South Florida St Petersburg
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University of South Florida
University of South Florida St Petersburg
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/281—Sorbents specially adapted for preparative, analytical or investigative chromatography
    • B01J20/286—Phases chemically bonded to a substrate, e.g. to silica or to polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
    • B01J20/3242—Layers with a functional group, e.g. an affinity material, a ligand, a reactant or a complexing group
    • B01J20/3244—Non-macromolecular compounds
    • B01J20/3246—Non-macromolecular compounds having a well defined chemical structure
    • B01J20/3257—Non-macromolecular compounds having a well defined chemical structure the functional group or the linking, spacer or anchoring group as a whole comprising at least one of the heteroatoms nitrogen, oxygen or sulfur together with at least one silicon atom, these atoms not being part of the carrier as such
    • B01J20/3261—Non-macromolecular compounds having a well defined chemical structure the functional group or the linking, spacer or anchoring group as a whole comprising at least one of the heteroatoms nitrogen, oxygen or sulfur together with at least one silicon atom, these atoms not being part of the carrier as such comprising a cyclic structure not containing any of the heteroatoms nitrogen, oxygen or sulfur, e.g. aromatic structures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
    • B01J20/3242—Layers with a functional group, e.g. an affinity material, a ligand, a reactant or a complexing group
    • B01J20/3268—Macromolecular compounds
    • B01J20/3272—Polymers obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2220/00—Aspects relating to sorbent materials
    • B01J2220/50—Aspects relating to the use of sorbent or filter aid materials
    • B01J2220/54—Sorbents specially adapted for analytical or investigative chromatography
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2220/00—Aspects relating to sorbent materials
    • B01J2220/80—Aspects related to sorbents specially adapted for preparative, analytical or investigative chromatography
    • B01J2220/84—Capillaries
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2220/00—Aspects relating to sorbent materials
    • B01J2220/80—Aspects related to sorbents specially adapted for preparative, analytical or investigative chromatography
    • B01J2220/86—Sorbents applied to inner surfaces of columns or capillaries

Definitions

  • the present invention relates to analytical separation and extraction technology. More specifically, the present invention relates to separation and extraction columns for use in separating and/or extracting components.
  • GC gas chromatography
  • Capillary GC is a separation technique in which the vapor phase of a sample in a gaseous, mobile phase passes through a capillary tube whose inner walls contain a thin film of an adsorbing or absorbing medium (i.e., stationary phase). Because of differential interactions of the sample components with the stationary phase, the individual components of the sample move through the column with different velocities. This leads to the physical separation of the sample components into individual chromatographic zones as they move down the column with their characteristic velocities. The separated components are detected instrumentally as they are eluted from the column.
  • deactivation is usually carried out as a separate step and involves chemical derivatization of the surface silanol groups.
  • Various reagents have been used to chemically deactivate the surface silanol groups (de Nijs; R.C.M., et al.; Schomburg, G. et al.; Blomberg, L. et al.; and Lee, M.L. et al.). Effectiveness of these deactivation procedures greatly depends on the chemical structure and composition of the fused silica surface to which they are applied. Of special importance are the concentration and mode of distribution of surface silanol groups.
  • the silanol group concentration on the drawn capillary surface can initially be low due to the formation of siloxane bridges under high-temperature drawing conditions. During subsequent storage and handling, some of these siloxane bridges can undergo hydrolysis due to reaction with environmental moisture. Thus, depending on the post-drawing history, even the same batch of fused silica capillary can have different concentrations of the silanol groups that can also vary by the modes of their distribution on the surface. Moreover, different degrees of reaction and adsorption activities are shown by different types of surface silanol groups (Lawrocki, J.).
  • the fused silica capillary is filled with a stationary phase solution prepared in a low-boiling solvent.
  • One end of the capillary is sealed using a high viscosity grease or by some other means (Abe, I. et al.) and the other end is connected to a vacuum pump.
  • the solvent begins to evaporate from the capillary end connected to the vacuum pump, leaving behind the stationary phase that becomes deposited on the capillary inner walls as a thin film.
  • Stationary phase film of desired thickness could be obtained by using a coating solution of appropriate concentration that can be easily calculated through simple equations (Ettre, L.S. et al.).
  • static-coated stationary phase films need to be stabilized immediately after their coating. This is usually achieved by stationary phase immobilization through free radical cross-linking (Wright, B.W. et al.) that leads to the formation of chemical bridges between coated polymeric molecules of the stationary phase.
  • stability of the coated film is achieved not through chemical bonding of the stationary phase molecules to the capillary walls, but mainly through an increase of their molecular size and consequently, through decrease of their solubility and vapor pressure.
  • Such an immobilization process has a number of drawbacks. First, polar stationary phases are difficult to immobilize by this technique (Yakabe, Y., et al.).
  • a preparation of a GC capillary column including a tube structure and a deactivated surface-bonded sol-gel coating on a portion of the tube structure forming a stationary phase was disclosed and claimed in PCT Application PCT/US99/19113, published as WO 00/11463, to Malik et al.
  • the invention disclosed therein is for a structure for forming a capillary tube, e.g., for gas chromatography, and a technique for forming such capillary tube.
  • the capillary tube includes a tube structure and a deactivated surface-bonded sol-gel coating on a portion of the tube structure to form a stationary phase coating on that portion of the tube structure.
  • the deactivated sol-gel stationary phase coating enables separation of analytes while minimizing adsorption of analytes on the separation column structure.
  • This type of column was a significant advancement in the art, but it was recognized that certain improvements would greatly enhance the performance of the sol-gel coated column.
  • sol-gel coatings with conventional stationary phases (e.g., sol-gel polydimethylsiloxane or sol-gel polyethylene glycol)
  • an additional selective organic ligands such as a dendrimer is desirable. Since the start of dendrimer chemistry, preparation of functional dendrimers has progressed and found use in a number of applications such as host-guest chemistry, carbohydrate chemistry (N. Jayaraman et al. and R. Roy et al.) (i.e., the so- called "sugar ball")(K. Aoi et al., 1995, K.
  • Various polysiloxane-based materials that are most commonly used as stationary phases in GC are prepared by chemically binding functional pendant groups to a polysiloxane backbone.
  • the used pendant groups are methyl (C.R. Trash), phenyl (AT. James), biphenyl (M.L. Lee et al.), cyanopropyl (K.E. Markides et al.), cyanobiphenyl (A. Malik et al., 1992), liquid crystalline moieties (J.S. Bradshaw et al.), chiral moieties (H. Frank et al., Koppenhoefer et al.), and molecular cavities including cyclodextrins (G.
  • non-silicone stationary phases are polyethylene glycols (S.B. Bendre, et al. and P. Sandra et al.), and molten salts of various organic acids (CF. Poole et al.).
  • open tubular gas chromatography which is the predominant format in current gas chromatography practice, a uniform, thin coating of the stationary phase is created on the inner surface of a fused silica capillary.
  • sol-gel coatings are characterized by significantly higher thermal and solvent stability (D. Wang et al., J.D. Hayes et al., 1997, and S.L. Chong et al.).
  • sol-gel approach to column technology being quite general, it is applicable to a wide range of techniques (J.D. Hayes et al., 1997, S.L. Chong et al., J.D. Hayes et al., 2001 , and J.D. Hayes et al., 2000), and allows for the column preparation both in open tubular (D. Wang et al., J.D. Hayes et al., 1997, and J.D. Hayes et al., 2001), and monolithic formats (J.D. Hayes et al., 2000).
  • a capillary column including a tube structure having an inner surface and a sol-gel substrate bonded to a dendrimer substrate to form a sol-gel dendrimer coating, wherein the sol-gel dendrimer coating bonds to a portion of the inner surface of the tube structure to form a surface-bonded stationary phase coating thereon.
  • the present invention further provides for a gas chromatography column including the capillary column and the sol-gel dendrimer matrix.
  • the present invention additionally provides for a capillary column including a tube structure having an inner surface, a stationary phase coating attached to at least a portion of the inner surface, and a dendrimer moiety chemically bonded to the stationary phase coating for selective interactions with various analytes.
  • a separation and extraction apparatus including a stationary phase of a sol-gel bonded to a dendrimer moiety wherein the stationary phase is bonded to a surface. Furthermore, a separation and extraction phase including a sol-gel bounded to a dendrimer moiety is provided.
  • the present invention also provides for a one-step method for preparing the capillary column described herein. Additionally, the present invention provides for a method of making a sol-gel and dendrimer solution and placement into the capillary column described herein. DESCRIPTION OF THE DRAWINGS
  • Figure 1 is a longitudinal, cross-sectional view of an embodiment of a capillary column of the present invention
  • FIG 2 is a schematic representation (Scheme 1) of the formation of a selected dendritic reagent or isocyanate monomer utilized in an embodiment of the present invention, wherein the isocyanate monomer (Structure 2) is formed by simple reduction of the alkyl nitro group to a corresponding amine that, with triphosgene, yields the desired isocyanate monomer (Structure 2);
  • Figure 3 is a schematic representation (Scheme 2) of the formation of a selected dendritic reagent or isocyanate monomer utilized in an embodiment of the present invention, wherein the isocyanate monomer formed is an isocyanate-9 benzyl ether (Structure 7);
  • Figure 4 is a schematic representation (Scheme 3) of the formation of a desired dendritic reagent or isocyanate monomer (Structure 12) utilized in an embodiment of the present invention, wherein the isocyanate monomer is an isocyanate-27 benzyl ether (Structure 12);
  • Figure 5A, 5B, and 5C are schematic representations (Scheme 4) of the synthesis of the dendritic silane reagents (Structure 3, Structure 8, and Structure 13) from selected dendritic reagents or isocyanate monomers (Structure 2, Structure 7, and Structure 12, respectively), wherein the synthesis occurs by treatment of isocyanate monomers possessing a focal isocyanate moiety and terminal benzyloxy groups with 3- triethoxysilylpropylamine;
  • Figure 6 is a schematic representation (Scheme 5) of a hydrolysis reaction of methyltrimethoxysilane to form a hydrolyzed methyltrimethoxysilane ( Figure 6a) and benzyl-terminated polymer to form a hydrolyzed benzyl-terminated dendron ( Figure 6b);
  • Figure 7A is a schematic representation (Scheme 6A) of a polycondensation reaction of the hydrolyzed methyltrimethoxysilane
  • Figure 7B is a schematic representation (Scheme 6B) of a polycondensation reaction of the hydrolyzed benzyl-terminated dendron;
  • Figure 8 is a schematic representation (Scheme 7) of a reaction of the polycondensation product with a capillary glass inner surface 14;
  • Figure 9 is a schematic representation (Scheme 8) of a deactivation of residual silanol groups, attached to a glass surface, utilizing 1 ,1,1 ,3,3,3- hexamethyldisilazane;
  • Figure 10 presents chromatograms illustrating the GC separation of
  • FIG. 11 illustrates a GC separation of a mixture of aldehydes on a phenyl-terminated sol-gel dendrimer stationary phase with conditions of: 10 m x 0.25 mm i.d.
  • fused silica capillary column temperature programming from 60°C @ 6°C/minutes; helium as the carrier gas; split injection (100:1), 300° C; flame ionization detector, 350° C, and peaks: (1) benzaldehyde, (2) p- tolualdehyde, 3) nonylaldehyde, (4) n-decylaldehyde, (5) dodecylaldehyde;
  • Figure 12 illustrates a GC separation of a mixture of ketones on a capillary column with phenyl-terminated sol-gel dendrimer stationary phase with conditions of: 10 m x 0.25 mm i.d. fused silica capillary column; temperature programming from 60° C @ 6°C/minutes; helium as the carrier gas, 40 cm/s; split injection (100:1), 300°C; flame ionization detector, 350°C, and peaks: (1) cyclohexanone, (2) 5-nonanone, (3) butyrophenone, (4) valerophenone, (5) heptanophenone;
  • Figure 13 illustrates a capillary GC separation of a mixture of aromatic amines on a phenyl-terminated sol-gel dendrimer stationary phase with conditions of: 10 m x 0.25 mm i.d. fused silica capillary column; temperature programming from 60°C @ 6°C/minutes; helium as the carrier gas, 40 cm/s; split injection (100:1), 300°C, flame ionization detector, 350°C, and peaks: (1) pyridine, (2) ⁇ /-methylaniline, (3) 2-ethylaniline, (4) 4-ethylaniline, (5) N- butylaniline;
  • Figure 14 illustrates a chromatogram of capillary GC separation of a mixture of alkanes on a phenyl-terminated sol-gel dendrimer stationary phase, wherein the conditions are: 10 m x 0.25 minutes i.d.
  • fused silica capillary column temperature programming from 80°C to 250°C at 10°C/minutes; helium as the carrier gas; split/splitness injection, 300°C; flame ionization detector, 350°C (Peaks: n-dodecane, (6) n-tridecane, (7) n-tetradecane, (8) n- pentadecane);
  • Figure 15 illustrates a GC separation of a mixture of polycyclic aromatic hydrocarbons on a capillary column with phenyl-terminated sol-gel dendrimer stationary phase with conditions of: 10 m x 0.25 mm i.d. fused silica capillary column; temperature programming from 80°C (0.5 minute hold) to 250°C at 10°C/minutes; helium as the carrier gas; split/splitless injection, 300°C; flame ionization detector, 350°C, and peaks: (1) naphthalene, (2) acenaphthene, (3) fluorene, (4) anthracene;
  • Figure 16 is a chromatogram illustrating the microextraction of PAHs utilizing an embodiment of a sol-gel dendrimer coating on a capillary column of the present invention, wherein the extraction conditions are: sol-gel dendrimer- coated extraction capillary of 13 cm X 250 ⁇ m i.d., extraction from water for 30 minutes, the GC conditions are: sol-gel PDMS coated column of 10 m X 250 ⁇ m i.d. at 30°C for 5 minutes @ 15°C/minute, splitless injection, 300°C, FID; 350°C, with peaks at: (1) acenapthene, (2) fluorene, (3) phenanthrene, (4) fluoranthrene, (5) pyrene;
  • Figure 17 is a chromatogram illustrating the microextraction of aldehydes utilizing an embodiment of the sol-gel dendrimer coated capillary column of the present invention, wherein the extraction conditions are: sol-gel dendrimer coated extraction capillary of 13 cm X 0.25 mm i.d., extraction from water for 30 minutes, the GC conditions are: sol-gel PDMS coated column of 10 m X 0.25 mm i.d.
  • Figure 18 is a chromatogram illustrating the microextraction of ketones utilizing an embodiment of the sol-gel dendrimer coated capillary column of the present invention, wherein the extraction conditions are: sol-gel dendrimer coated extraction capillary of 13 cm X 0.25 mm i.d., extraction from water for 30 minutes, the GC conditions are: sol-gel PDMS coated column of 10 m X 0.25 mm i.d.
  • Figure 19 is a chromatogram illustrating the microextraction of alcohols utilizing an embodiment of the sol-gel dendrimer coated capillary column of the present invention wherein the extraction conditions are: sol-gel dendrimer coated extraction capillary of 13 cm X 0.25 mm i.d., extraction from water for 30 minutes, the GC conditions are: sol-gel PEG coated column of 10 m X 0.25 mm i.d.
  • Figure 20 is a chromatogram illustrating the microextraction of phenols utilizing an embodiment of the sol-gel dendrimer coated capillary column of the present invention wherein the extraction conditions are: sol-gel dendrimer coated extraction capillary of 13 cm X 0.25 mm i.d., extraction from water for 30 minutes, the GC conditions are: sol-gel PEG coated column of 10 m X 0.25 mm i.d. at 30°C for 5 minutes @ 15°C/minute, splitless injection, 300°C, FID; 350°C, with peaks at: (1) 2-chlorophenols, (2) 2,5-dimethylphenol, (3) 3,4- dichlorophenol, (4) 2,4,6-trichlorophenol, (5) 4-chloro-3-methylphenol;
  • Figure 21 is a chromatogram illustrating the microextraction of 2,6-Di- tert-butyl-p-cresol (BHT) utilizing an embodiment of the sol-gel dendrimer coated capillary column of the present invention, wherein the extraction conditions are: sol-gel dendrimer coated extraction capillary of 13 cm X 0.25 mm i.d., extraction from water for 30 minutes, the GC conditions are: sol-gel PDMS coated column of 10 m X 0.25 mm i.d. at 30°C for 5 minutes @ 15°C/minute, splitless injection, 300°C, FID; 350°C;
  • BHT 2,6-Di- tert-butyl-p-cresol
  • Figure 22 is a graph illustrating the extraction kinetics of fluorene on an embodiment of a sol-gel dendrimer coated capillary column of the present invention.
  • Figure 23 is a graph illustrating the extraction kinetics of 2,4,6- trichlorophenol on an embodiment of a sol-gel dendrimer coated capillary of the present invention.
  • the present invention provides for a separation and extraction phase including a sol-gel bounded to a dendrimer moiety. Further, a separation and extraction apparatus including a stationary phase of a sol-gel bonded to a dendrimer moiety wherein the stationary phase is bonded to a surface.
  • a sol-gel dendron separation and extraction capillary column constructed in accordance with the present invention is indicated at 10 in Figure 1.
  • the capillary column 10 separates and/or extracts analytes, substances, or other components from a solution.
  • the capillary column 10 includes a tube structure 12 having an inner surface 14 and a sol- gel dendrimer stationary phase coating 16 or sol-gel dendrimer matrix 16 attached to at least a portion of the inner surface 14 to coat the inner surface 14 thereon.
  • the sol-gel dendrimer stationary phase coating 16 or sol-gel dendrimer matrix 16 includes a sol-gel substrate 18 bonded to a dendrimer mechanism 20 or substrate 20.
  • the sol-gel substrate 18 chemically bonds and attaches to the inner surface 14 of the tube structure 12.
  • the dendrimer mechanism 20 or substrate 20 selectively binds to a selected ligand, component, analyte, or other substance known to those of skill of the art.
  • the present invention provides for the synthesis, extended silane functionalization, and facile attachment procedures for highly branched isocyanate monomers.
  • the isocyanates have terminal benzyl ether groups, but any similar isocyanate monomer can be used with the present invention.
  • the present invention provides for the in situ creation of sol-gel dendrimer stationary phase coatings for high-resolution capillary gas chromatography.
  • the present invention also provides for a simple, one-step procedure that leads to the creation of a surface-bonded sol-gel dendritic stationary phase on an inner surface of a fused silica capillary.
  • Such a stationary phase provides for unique selectivity in gas chromatography (hereinafter, "GC"), which results from the highly branched structures of the isocyanate monomers. A marked difference is observed in the chromatographic selectivity of these sol-gel stationary phases containing different generation dendrons.
  • the present invention provides for achievement of enhanced performance and selectivity in chromatographic separations through the use of sol-gel dendritic stationary phases.
  • the key aspect of the present invention is the use of sol-gel substrates in conjunction with functionalized dendrimers having a tree-like branched architecture.
  • the use of both the sol-gel substrate along with the functionalized dendrimers in separation columns serve as high-performance stationary phases in analytical separations.
  • the dendrimers are preferably attached as stationary phases in columns incorporating the desired terminal groups.
  • the present invention is useful for capillary systems as well as any other chromatography system that employs the use of polysiloxane-based, PEG-based, and other types of stationary phases for separation.
  • the present invention has numerous applications and uses.
  • the present invention is useful in separation processes involving analytes including, but not limited, to hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), alcohols, aldehydes, ketones, phenols, fatty acids, fatty acid methyl esters, amines, and other analytes known to those of skill in the art.
  • the capillary column 10 of the present invention can be used for both gas chromatographic separations and for solventless sample preconcentration via capillary microextraction.
  • Figures 10 to 15 illustrate the use of the capillary column 10 of the present invention for GC separations
  • Figures 16 to 21 illustrate applications of capillary column 10 for sample microextraction or preconcentration.
  • capillary microextraction kinetics are illustrated in Figures 22 and 23.
  • Tables 1 and 2 low parts per trillion detection limits can be obtained for various classes of compounds by capillary microextraction using the capillary column 10 of the present invention. Accordingly, the present invention is useful in chemical, petrochemical, environmental, pharmaceutical applications, and other similar applications.
  • the present invention has various advantages over the prior art.
  • the present invention provides for a fast way of surface roughening, deactivation, coating, and stationary phase immobilization - all carried out in a single step.
  • the present invention can achieve all of these just by filling a capillary with a sol-gel dendritic solution of appropriate composition, and allowing it to stay inside the capillary for a controlled period, followed by inert gas purging and conditioning of the capillary.
  • the present invention greatly simplifies the methodology for the preparation of high efficiency GC columns, and offers an opportunity to reduce the column preparation time at least by a factor of ten.
  • the present invention is very suitable for automation and mass production.
  • Columns prepared by the present invention provide significantly superior thermal stability due to direct chemical bonding of the stationary phase coating to the capillary walls.
  • Enhanced surface area of the columns provides a sample-capacity advantage to the sol-gel columns.
  • the present invention provides excellent surface deactivation quality, which is either comparable with or superior to that obtained by conventional techniques. This is supported by examples of high efficiency separations obtained for polar compounds including free fatty acids, amines, alcohols, diols, phenols, aldehydes and ketones.
  • the sol-gel dendrimer capillary column has the potential to offer a viable alternative to existing methods for column preparation in analytical microseparation and/or microextraction techniques.
  • the present invention has numerous embodiments, depending upon the desired application. As described below, the formation of the various embodiments are intended for use in gas chromatography. However, due to the vast applicability of the present invention, the column and related methods thereof can be modified in various manners for use in other areas of analytical separation, extraction, and/or pre-concentration technologies. The principles of the present invention can also be used to form capillary columns for use in liquid chromatography, capillary electrochromatography, supercritical fluid chromatography, and as sample pre-concentrators where a compound of interest is present in very small concentrations in a sample.
  • the present invention can be utilized any type of structure having a surface that is capable of being coated by the sol-gel dendrimer coating of the present invention.
  • the structure can include, but is not limited to, a tube, a planar surface, a sphere, a plate, a coiled surface, a ring, an enclosed structure, an unenclosed structure, and any other structure having a suitable surface capable of being coated by the sol-gel dendrimer coating.
  • any portion of the surface (i.e., exterior and/or interior) of the structure can be coated with the sol-gel dendrimer coating of the present invention.
  • an interior or exterior portion of a tube can be coated.
  • two separate plates can be coated with the sol-gel dendrimer coating on a portion of a surface of each plate. Then, the plates can be sandwiched together to create a void or interior region for use in separations and/or extractions.
  • the material of the structure it can be made of any type of silica, glass, metal, alumina, fused silica, titania, zirconia, polymeric hollow fibers, and any other similar materials known to those of skill in the art.
  • a sol-gel substrate 18 formed from sol-gel precursors that is attached to a portion of a surface 14 of a structure 12; and (2) a dendrimer mechanism 20, substrate 20, or moiety 20 formed from an isocyanate monomer.
  • the dendrimer mechanism 20, substrate 20, or moiety 20 is bonded to the sol-gel substrate 18 and provides for a mechanism that selectively binds to various ligands, analytes, components, and other substances known to those of skill in the art.
  • sol-gel substrate has the formula:
  • X Residual of a deactivation reagent (e.g., polymethylhydrosiloxane (PMHS), hexamethyldisilazane (HMDS), etc.);
  • a deactivation reagent e.g., polymethylhydrosiloxane (PMHS), hexamethyldisilazane (HMDS), etc.
  • Y Sol-gel reaction residual of a sol-gel active organic molecule (e.g., molecules with hydroxysilane or alkoxysilane monomers, polydimethylsiloxane (PDMS), polymethylphenylsiloxane (PMPS), polydimethyldiphenylsiloxane (PDMDPS), polyethylene glycol (PEG) and related polymers such as Carbowax 20M, polyalkylene glycol such as Ucon, macrocyclic molecules such as cyclodextrins, crown ethers, calixarenes, alkyl moieties such as octadecyl, octyl, a residual from a baseline stabilizing agent such as bis(trimethoxysilylethyl)benzene, 1 ,4- bis(hydroxydimethylsilyl)benzene, etc.
  • a baseline stabilizing agent such as bis(trimethoxysilylethyl)benzene, 1 ,4- bis(hydroxydi
  • Z Sol-gel precursor-forming chemical element (e.g., Si, Al, Ti,
  • I An integer > 0;
  • n An integer > 0;
  • n An integer > 0;
  • I, m, n, p, and q are not simultaneously zero.
  • sol-gel solutions In the preparation of gas chromatography columns, it is desirable to use sol-gel solutions to coat the walls of capillary tube structures for the separation of analytes.
  • sol-gels are prepared by standard methods known in the art and comprise both polysiloxane and non-polysiloxane type gels. These include, but are not limited to, polysiloxane-based gels with a wide range of substituted functional groups, including: methyl, phenyl, cyanoalkyl, cyanoaryl, etc.
  • sol-gel polyethylene glycols such as, but not limited to, PEG, Carbowax, Superox, sol-gel alkyl, sol-gel polyalkylene oxides, such as Ucon, and other sol-gels, such as sol-gel dendrimers can be modified by the instant invention.
  • the precursors utilized for preparing the sol-gel coated GC capillary columns of the present invention have the general structure of:
  • Z is the precursor-forming element taken from a group including, but not limited to, silicon, aluminum, titanium, zirconium, vanadium, germanium, and the like; and R ⁇ , R2, R3, and R 4 (i.e., "R-groups") are substituent groups up to two of which are sol-gel-active, wherein the sol-gel active groups include, but are not limited to, alkoxy, hydroxy moieties, and the like.
  • Typical sol-gel-active alkoxy groups include, but are not limited to, a methoxy group, ethoxy group, n- Propoxy group, /so-Propoxy group, n-butoxy group, so-butoxy group, tert- butoxy group, and any other alkoxy groups known to those of skill in the art. If there are any remaining R-groups, they can be any non sol-gel active groups such as methyl, octadecyl, phenyl, and the like. It is preferred however, that three or four of the R-groups are sol-gel active groups.
  • Typical non-sol-gel-active substituents of the precursor-forming element include, but are not limited to, alkyl moieties and their derivatives, alkenyl moieties and their derivatives, aryl moieties and their derivatives, arylene moieties and their derivatives, cyanoalkyl moieties and their derivatives, fluoroalkyl moieties and their derivatives, phenyl moieties and their derivatives, cyanophenyl moieties and their derivatives, biphenyl moiety and its derivatives, cyanobiphenyl moieties and their derivatives, dicyanobiphenyl moieties and their derivatives, cyclodextrin moieties and their derivatives, crown ether moieties and their derivatives, cryptand moieties and their derivatives, calixarene moieties and their derivatives, liquid crystal moieties and their derivatives, dendrimer moieties and their derivatives, cyclophane moieties and their derivatives, chiral moie
  • precursors include, but are not limited to, a chromatographically active moiety selected from the group of octadecyl, octyl, cyanopropyl, diol, biphenyl, and phenyl.
  • Other representative precursors include, but are not limited to, Tetramethoxysilane, 3-(N-styrylmethyl-2-aminoethylamino)-propyltrimethoxysilane hydrochloride, ⁇ etradecyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, N-(3- trimethoxysilylpropyl)-N-methyl-N,N-diallylammonium chloride, N- trimethoxysilylpropyltri-N-butylammonium bromide, N-trimethoxysilylpropyl- N,N,N-trimethylammonium chloride, Trimethoxysilylpropylthiouronium chloride, 3-[2-N-benzyaminoethylaminopropyl]trimethoxysilane hydrochloride, 1 ,4- Bis(hydroxydimethylsilyl)benzene, Bis(2-hydroxyethyl)-3
  • the deactivation reagents include, but are not limited to, hydrosilanes, polymethylhydrosiloxlanes, polymethylphenyl hydrosiloxanes, polymethyl cyanopropyl hydrosioloxanes, and any other similar deactivation reagent known to those of skill in the art.
  • the primary catalyst includes, but is not limited to, trifluoroacetic acid, any acid, base, fluoride, and any other similar catalyst known to those of skill in the art.
  • the performance of the sol gel stationary phase can be improved by the addition of at least one baseline stabilizing reagent and at least one additional surface deactivation reagent to the sol-gel solution.
  • the baseline-stabilizing reagent prevents rearrangement of the sol-gel polymeric stationary phase and formation of volatile compounds at elevated temperature. In order to do so, the baseline- stabilizing reagent incorporates with the phenyl ring in the polymer backbone structure at room temperature using a sol-gel process.
  • the baseline- stabilizing reagent includes, but is not limited to, bis(trimethoxysilylethyl)- benzene (BIS), phenyl-containing groups, cyclohexane containing groups, and any other similar sol-gel active stabilizing reagent known to those of skill in the art.
  • the baseline-stabilizing reagent is used in conjunction with methyltrimethoxysilane (a sol-gel precursor), and two sol-gel catalysts (trifluoroacetic acid and ammonium fluoride).
  • a sol-gel precursor methyltrimethoxysilane
  • two sol-gel catalysts trifluoroacetic acid and ammonium fluoride.
  • the second sol-gel catalyst includes, but is not limited to, ammonium fluoride, base, fluoride, and any other similar catalysts known to those of skill in the art. It is known that under acidic conditions the hydrolysis reaction proceeds faster to produce primarily linear polymeric structure, but the polycondensation reaction remains slow. The addition of fluoride increases the polycondensation reaction rate.
  • a surface derivatization reagent can be added as a secondary deactivation reagent, which includes, but is not limited to, 1 ,1 ,1 ,3,3,3- heaxmethyldisilazane, any hydrosilane, and any other similar surface deactivation reagents known to those of skill in the art.
  • the sol-gel reactions involved in the formation of the sol-gel structure and resulting sol-gel and dendrimer substrate described herein and chemical bonding of the sol-gel and dendrimer substrate to a portion of the inner surface of the capillary column are illustrated in the Figures.
  • the preparation of the sol-gel coating includes the steps of providing the tube structure, providing a sol-gel solution including one or more sol-gel precursors, an organic material with at least one sol-gel active functional group, one or more sol-gel catalysts, one or more deactivation reagents, and a solvent system.
  • the sol-gel solution is then reacted with a portion of the tube (e.g., inner surface) under controlled conditions to produce a surface bonded sol-gel coating on the portion of the tube.
  • the free portion of the solution is then removed from the tube under pressure, purged with an inert gas, and is heated under controlled conditions to cause the deactivation reagent to react with the surface bonded sol-gel coating to deactivate and to condition the sol- gel coated portion of the tube structure.
  • the sol-gel precursor includes an alkoxy compound.
  • the organic material includes a monomeric or polymeric material with at least one sol-gel active functional group.
  • the sol- gel catalyst is taken from the group consisting of an acid, a base and a fluoride compound, and the deactivation reagent includes a material reactive to polar functional groups (e.g., hydroxyl groups) bonded to the sol-gel precursor- forming element in the coating or to the tube structure.
  • Dendrimer and Isocyanate Monomer The dendrimers utilized with the present invention have been prepared according to the procedures and examples presented in U.S. Patent Numbers 5,136,096 to Newkome et al., 5,650,101 to Newkome et al., 5,703,271 to Newkome et al., and 5,773,551 to Newkome et al., all of which are incorporated herein by reference in their entirety.
  • the dendrimer is a cascade molecule or isocyanate monomer synthesized by reacting at least one tier of a functionalized structure with compounds of the type:
  • the dendrimer or isocyanate monomer can be single or multi-branched. Additionally, it can have numerous functions including, but not limited to, being a selective micelle for selectively attaching to a ligand and a lock and key micelle.
  • the micelle includes an acceptor region being disposed within an engineered void region to define a pocket that allows entrance thereto of a specific ligand based on the ligands' structure and a binding region that is complementary to the acceptor region.
  • cascade molecules or polymers such cascade molecules can be used to provide a (uni)molecular micelle including internal void areas, the void areas including reactive sites capable of covalent and non-covalent bonding to guest(s).
  • Such (uni)molecular micelles made in accordance with the present invention are cascade structures that act as micelles.
  • Such molecules are essentially all alkyl molecules having a nitrogen or carbon core or branching site.
  • Such compounds have predefined branching, depending upon the number of sequential "tier" additions that are performed. That is, the synthetic process is a matter of assembling the molecule in tiers or layers in accordance with the inventive method described herein.
  • etymology of the term "Micelle”, as employed in the classical or usual sense refers to a non-covalently associated collection (aggregate) of many simple molecules functioning as a unit having unique properties (for example, aqueous solubilization of water in soluble materials) that are not observed with the individual molecules that comprise the micelle.
  • (uni)molecular micelle refers to a single macromolecule, possessing a covalently constructed superstructure that can perform the same function or functions as a classical micelle.
  • micelles or cascade polymers made in accordance with the present invention can be described as having at least one core atom, preferably a carbon atom, and arms branching from the core atom.
  • cascade refers to the tiering or layer-wise addition of monomers or "building blocks" that eventually comprise the resulting unimolecular micelle.
  • a quasi-tertiary domain comprises one of the major domains of the micellar macromolecular structure that includes the immediate region above the micellar surface, the micellar per se and the micellar framework. All of these domains are active in that they can be used to effect chemical and physical changes of the (uni)molecular micelle, its environment, a molecular guest or guests, or any of the cited combinations.
  • Termination of the arms of the micelles, or with larger branching, possibly mid-portions of the arms, may fold to form an outer surface of the micelle or cascade structure.
  • the surface of the micelle is exposed to the immediately surrounding environment in which the micelle is disposed. This environment will have a certain hydrodynamic character, determined by properties such as pH, lipophilicity-hydrophilicity characteristics. Such surface characteristics also lead to general solubility of the micelle, even when carrying a relatively insoluble guest therein. Such surfaces can be readily coated with metal ions. Thus, incorporation of specific types of metals or nonmetals within the chemically accessible lipophilic interior of the unimolecular micelle can also be achieved.
  • Synthesis of the combined sol-gel dendrimer coating 16 or matrix 16 is described in more detail in the examples section and illustrated in the Figures.
  • synthesis occurs by reaction of the various dendritic reagents or isocyanate monomers (Structure 2, Structure 7, and Structure 12, respectfully) with a sol-gel substrate 18 such as 3-triethoxysilylpropylamine.
  • the dendritic reagent or isocyanate monomer possesses a focal isocyanate moiety and terminal benzyloxy groups.
  • the sol-gel dendron separation and extraction capillary column 10 includes the tube structure 12 having the inner surface 14 and a sol-gel dendrimer stationary phase coating 16.
  • the sol-gel dendrimer coating 16 is attached to the inner surface 14 by means of the sol-gel substrate 18.
  • the dendrimer is an isocyanate monomer having a terminal benzyl ether group attached thereto. Depending upon the desired selectivity, the number of benzyl ether groups varies accordingly and extensive branching can occur.
  • the tube structure 12 of the capillary column 10 can have any shape including, but not limited to, cylindrical, spherical, conical, funnel-shaped, pyramid-shaped, polygonal-shaped, coiled, elongate-quadrangular-shaped, oblong, and any other similar shape known to those of skill in the art.
  • the tube structure 12 can be made of numerous materials including, but not limited to alumina, fused silica, glass, titania, zirconia, polymeric hollow fibers, and any other similar tubing materials known to those of skill in the art. Typically, fused silica is the most convenient material used.
  • Sol-gel chemistry in analytical microseparations and/or microextractions presents a universal approach to creating advanced material systems including those based on alumina, titania, and zirconia that have not been adequately evaluated in conventional separation column technology.
  • the sol-gel chemistry- based column technology has the potential to effectively utilize advanced material properties to fill this gap.
  • the sol-gel dendrimers or various polysiloxane-based materials are attached to a GC column.
  • the various materials that are most commonly used as stationary phases in GC are prepared by chemically binding functional pendant groups to a polysiloxane backbone.
  • the pendant groups used include, but are not limited to, methyl, phenyl, biphenyl, cyanopropyl, cyanobiphenyl, dicyanobiphenyl, liquid crystalline moieties, chiral moieties, and molecular cavities including cyclodextrins, crown ether, calixarenes, and cyclophanes.
  • Non-silicone stationary phases used include, but are not limited to, polyethylene glycols and molten salts of various organic acids.
  • Isocyanate monomers having terminal benzyl ether moiety, are utilized as depicted in Schemes 2 and 3, Figures 3 and 4 respectively.
  • a larger structure, 9-benzyl ether (Structure 5), and even larger analogue (Structure 10) were synthesized from Structure 4 and Structure 9 (Newkome et al., 1991) respectively, by reacting each with 4-amino-4-[3- (benzyloxy)propyl]-1 ,7-di(benzyloxy)heptane (Newkome et al., 1992) using DCC coupling in anhydrous DMF at 25°C for 48 hours.
  • Structure 5 and Structure 10 are confirmed by the upfield shift of carbonyl carbon, confirming the acid to amide conversion, and the downfield shift ( 13 C NMR: ⁇ 5-6 ppm) of the C 4° - NH 2 .
  • the identification of both structures was further supported by the peaks at m/z 1673.1 [M + Na + ] (5: calcd. m/z 1673.2 [M + Na + ⁇ and m/z 5106.6 [M + NaT (10: calcd. m/z 5106.8 [M + Na + ]) in ESI-MS and MALDI-TOF, respectively.
  • the IR spectrum for each showed the typical isocyanate peak at 2257 and 2248 cm “1 and the ESI-MS and MALDI-TOF further confirms their assignment by a peak at m/z 1646.2 [M + ] (7: calculated, m/z 1646.2 [M + ]) and m/z 5080.2 (12: calculated. m/z5080.8 [M + H + ]), respectively.
  • Dendritic silane reagents (Structure 3, Structure 8, and Structure 13) are synthesized by treatment of these monomers possessing the focal isocyanate moiety and terminal benzyloxy groups with 3- triethoxysilylpropylamine in dry CH 2 CI 2 at 25°C for 1 hour.
  • the sol-gel active dendritic reagents (Structure 2, Structure 7, or Structure 12) and MTMS undergo hydrolysis catalyzed by TFA.
  • the hydrolyzed products further undergo polycondensation reaction to form an organic-inorganic hybrid polymer network with the dendrimers, as the organic constituents do.
  • the condensation reaction can also take place with the participation of the silanol groups on the inner surface of the fused silica capillary.
  • the sol-gel dendritic network developed in the vicinity of the fused silica capillary inner surface get chemically anchored to the column walls forming a surface-bound stationary phase film, and remain as such when the sol-gel solution is expelled after 15 minutes of residence inside the capillary.
  • Polymethylhydrosiloxane (PMHS) used in the coating solution is not sol-gel active.
  • the physically incorporated molecules of this material deactivate the column by reacting with the residual silanol groups on the coated surface during the thermal conditioning that follows the coating process.
  • the sol-gel procedure elegantly combines column deactivation, coating and stationary film immobilization in a simple and effective manner.
  • Figures 10A, 10B, and 10C present three gas chromatograms obtained on three different sol-gel columns with the first- (2)(A), second- (7) (B), and third (12) generation (C) benzyl- terminated dendritic appendages, as part of the stationary phases.
  • Grob test mixture (Grob et al.) containing compounds from different chemical classes was used as the sample probe.
  • the sol-gel dendrimer stationary phase can provide well-behaved chromatographic peaks for both polar and non-polar components. The elution pattern for individual components of this mixture is very different from that obtained on conventional columns.
  • the first eluting component is n- decane.
  • the sol-gel dendrimer column behaves similar to a polar column (e.g., PEG type) characterized by early elution of n-alkanes.
  • a marked difference in chromatographic efficiency is observed in columns prepared with sol-gel dendrimer stationary phases containing different generations of dendritic moieties. For example, an efficiency value of 3,200 theoretical plates/m is obtained on a 10 m x 0.25 m i.d. column coated with the third generation sol-gel dendrimer stationary phase. This corresponded to a minimum plate height of 0.31 mm and an optimum flow rate of 25 cm/s. Efficiency values on the order of only 1 ,000 plates/m were obtained on the columns coated with the first and second generation stationary phases.
  • Figures 11 and 12 represent GC separations of aldehydes and ketones, respectively, on a phenyl-terminated third generation sol-gel dendrimer stationary phase. Sharp symmetrical peaks of the aldehyde and ketone peaks are indicative of quality deactivation and performance of the sol-gel dendritic stationary phase used. Analysis of aldehydes and ketones is important both from industrial and environmental points of view. HPC is frequently employed for this purpose (Koivusalmi et al.); however, HPLC analysis often requires a prior derivatization of the separation mixture making the analysis more complicated and time consuming. The UV detector frequently employed in HPLC is much less sensitive than the flame ionization detector used in GC analysis. This makes GC analysis of underivatized aldehydes and ketones more practical and attractive. GC separation of a mixture of aromatic amines is represented in Figure
  • the dendritic reagent possessed simply benzyl ether termini and urea connectivity, it can be concluded that the dendritic architecture provides unique selectivity in capillary GC separations and makes these materials very useful in chromatographic and electromigration separations and/or extractions.
  • the dendritic architecture provides unique selectivity in capillary GC separations and makes these materials very useful in chromatographic and electromigration separations and/or extractions.
  • Use of these complimentary supramolecular relationships into the environment analyte species for chromatographic interactions can lead to enhanced selectivity in separations and/or extractions.
  • sol-gel chemistry to chemically bind these molecules to the capillary inner surface in the form of a stable organic-inorganic hybrid stationary phase coating opens new possibilities for enhanced performance and stability in differential migration separation and/or extraction techniques.
  • the specific steps for fabrication starts with the cleaning and hydrothermal treatment of a fused silica capillary. Then, the preparation of the sol-gel solution utilizing the above precursors is done. Next, the inner walls of the hydrothermally treated capillary column are coated with the prepared sol- gel solution. Finally, conditioning of the sol-gel coated capillary tube is performed.
  • the creation of a surface-bonded sol-gel dendrimer coating on the inner walls of a fused silica capillary involves the steps of (1 ) mixing suitable sol-gel precursor(s) and sol-gel active dendritic moieties to form a sol-gel solution; (2) hydrolyzing the sol-gel-active precursor(s) and dendritic moieties to form hydrolyzed products (Scheme 5); (3) polycondensating the hydrolyzed products into a sol-gel dendrimer network (Schemes 6a and 6b); and
  • Deactivation of the residual silanol groups on the surface coating is represented by Scheme 8.
  • the hydrolysis and polycondensation reactions take place within the sol-gel solution placed inside the fused silica capillary, while the deactivation reaction takes place at elevated temperatures during the column conditioning carried out at a later step in the column preparation process.
  • the mixing step further includes adding trifluoroacetic acid as a catalyst alone, or in conjunction with an additional catalyst including, but not limited to, acids, bases, and fluorides.
  • a Fisher Model G-560 Vortex Genie 2 system is used for thorough mixing of the sol-gel solution ingredients while preparing the sol-gel solution.
  • a homemade gas-pressure operated filling/purging device J.D. Hayes et al. is used for filling the fused silica capillary with the sol-gel solution, as well as rinsing and purging with helium at various stages of column preparation.
  • silane-3-benzyl ether (Structure 3) is initially formed.
  • Method B Nitro-9-benzyl ether (Structure 5) Amidation method to form nitro-9-benzyl ether (Structure 5) from an acid (Structure 4).
  • acid (Structure 4) (1.00 g, 3.60 mmol) in dry DMF (50 mL)
  • DCC (2.46 g, 11.84 mmol)
  • 1-HOBT (1.60 g, 11.84 mmol) at 25°C are added.
  • the solution is stirred for two hours, and then amine (Structure 1 ) (5.69 g, 11.96 mmol) is added.
  • the stirred solution is maintained for 48 hours, after which a white precipitate is filtered.
  • a reduction reaction occurs to form the amine-9-benzyl ether wherein a sonicated solution of NiCI 2 «6H 2 0 (144 mg, 610 ⁇ mol) in MeOH (30 mL) is prepared. NaBH 4 (69 mg, 1.82 mmol) is added portion-wise, resulting in the formation of a black suspension of NiB. The suspension is sonicated for an additional 30 minutes, then a solution containing Structure 5 (1.80 g, 1.09 mmol) in EtOH-toluene (10:1 ; 22 mL) is added. The mixture is stirred at 50°C, while adding NaBH 4 (460 mg, 12.12 mmol) portion-wise over three hours.
  • Structure 8 is formed and isolated (99%) as a colorless oil: 790 mg; 1 H NMR ⁇ 0.59 (t, 2H, SiCH 2 CH 2 CH 2 ), 1.19 (m, 11 H, CH 3 CH 2 0, SiCH 2 CH 2 CH 2 ), 1.47 (s, 18H, CH 2 CH 2 CH 2 0), 1.67 (s, 18H, CH 2 CH 2 CH 2 0), 1.92 (s, 6H, CH 2 CH 2 CONH), 2.09 (s, 6H, CH 2 CH 2 CONH), 3.07 (t, 2H, SiCH 2 CH 2 CH 2 ), 3.40 (s, 18H, CH 2 CH 2 CH 2 0), 3.78 (q, 6H, CH 3 CH 2 0), 4.43 (s, 18H, OCH 2 Ph), 6.13 (s, 3H, CONH), 7.29 (m, 45H, Ph); 13 C NMR ⁇ 7.3 (SiCH 2 CH 2 CH 2 ), 17.9 (CH 3 CH 2 0), 23.3 (CH 2 CH 2 CH 2 0,
  • Three separate sol-gel solutions are prepared using three different dendritic reagents, each containing a triethoxysilane group at the root.
  • 100 mg of the selected dendritic reagent (Structure 2, Structure 7, or Structure 12) is dissolved in CH 2 CI 2 (100 ⁇ L) and placed in a microcentrifuge tube (1.5 mL).
  • PMHS 40 ⁇ L
  • MTMS 100 ⁇ L
  • TFA 100 ⁇ L
  • containing 5% water is added to the centrifuge tube and vortexed again.
  • the contents of the tube are then centrifuged four minutes at 13,000 rpm (15,682 G) to separate any precipitate that may have formed during the mixing process.
  • the clear sol-gel solution from the top of the centrifuge tube is then transferred to a clean vial for further use.
  • the sol-gel dendritic solution is used to prepare open tubular GC column following a general procedure described in an earlier publication (D. Wang et al.)
  • a hydrothermally treated fused silica capillary (10 m x 250 ⁇ M i.d.) is filled with the sol-gel dendritic solution using a homemade filling/purging device (J.D. Hayes et al.) under 100 psi helium pressure.
  • the solution remains inside the capillary for 15 minutes; afterwards, it is expelled from the capillary under helium pressure.
  • the capillary is dried by purging it with helium for 30 minutes at 25°C Then, the capillary is conditioned thermally under a continuous flow of helium: from 40 to 280°C at 1 °C minutes "1 , holding the column at the final temperature for five hours. Finally, the column is rinsed with CH 2 CI 2 and dried under a helium purge. At this point, the column is ready for analytical use.
  • Table 1 Run to run & capillary to capillary peak area repeatability, retention time repeatability, and detection limit data for ppb and sub-ppb level concentrations of PAH's , aldehydes, and ketones in five replicate measurements by OTME-GC using sol-gel dendrimer coatings
  • Table 2 Run to run & capillary to capillary peak area repeatability, retention time repeatability, and detection limit data for ppb and sub-ppb level concentrations of phenols, alcohols, and preservatives in five replicate measurements by OTME-GC using sol-gel dendrimer coatings

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Abstract

L'invention porte sur une colonne capillaire (10) consistant en un tube (12) présentant une surface intérieure (14) et un substrat (18) de sol-gel lié à un substrat de dendrimère de manière à former une matrice (16) de sol-gel dendrimère (16) liée à une partie de la surface intérieure (14) du tube (12) et formant sur ce dernier un revêtement en phase stationnaire lié à la surface. L'invention porte également sur un appareil de séparation/extraction comportant une phase stationnaire de sol-gel (18) liée à un fragment (20) de dendrimère, ainsi que sur un procédé d'obtention d'une solution de sol-gel et de dendrimère.
PCT/US2002/015818 2001-05-18 2002-05-16 Colonne capillaire de separation/extraction a dendrites de sol-gel Ceased WO2002094410A1 (fr)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7244295B2 (en) * 2003-01-07 2007-07-17 The Research Foundation Of State University Of New York Hybrid anti-fouling coating compositions and methods for preventing the fouling of surfaces subjected to a marine environment
US7947174B2 (en) 2000-02-09 2011-05-24 University Of South Florida Sol-gel monolithic column with optical window and method of making
US8685240B2 (en) 2001-03-09 2014-04-01 University Of South Florida High efficiency sol-gel gas chromatography column
US10058843B2 (en) 2013-09-20 2018-08-28 Van So Le Multifunctional sorbent materials and uses thereof
CN109865315A (zh) * 2017-12-05 2019-06-11 中国科学院大连化学物理研究所 一种用作色谱固定相的有机-无机杂化介孔材料涂层制备方法
CN109876772A (zh) * 2019-04-22 2019-06-14 北京石油化工学院 纳米碳纤维与活性炭复合材料及其制备方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4043905A (en) * 1974-08-26 1977-08-23 Indiana University Foundation Chromatographic separation columns with selectively modified active surfaces and methods for their preparations
US4746572A (en) * 1986-11-28 1988-05-24 E. I. Dupont De Nemours And Company Structures surface modified with bidentate silanes
US4756971A (en) * 1984-12-28 1988-07-12 Ksv-Chemicals Oy Surface treatment agents and polymers comprising substituted phenyl silanes and siloxanes
US5082559A (en) * 1989-08-25 1992-01-21 U.S. Philips Corporation Glass chromatography capillary with relatively thick coating
US5224972A (en) * 1990-09-11 1993-07-06 Frye Gregory C Coatings with controlled porosity and chemical properties
US5308495A (en) * 1990-01-23 1994-05-03 Yissum, Research Development Company Of The Hebrew University Of Jerusalem Chromatography processes using doped sol gel glasses as chromatographic media
US5338454A (en) * 1992-08-27 1994-08-16 Supelco, Incorporated Chiral mobile phase additives for improved liquid-chromatography separations
US5770084A (en) * 1995-01-01 1998-06-23 Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College Polymerized chiral micelles for chiral separations
US5886127A (en) * 1996-08-28 1999-03-23 University Of South Florida Combinatorial method of forming cascade polymer surfaces

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4043905A (en) * 1974-08-26 1977-08-23 Indiana University Foundation Chromatographic separation columns with selectively modified active surfaces and methods for their preparations
US4756971A (en) * 1984-12-28 1988-07-12 Ksv-Chemicals Oy Surface treatment agents and polymers comprising substituted phenyl silanes and siloxanes
US4746572A (en) * 1986-11-28 1988-05-24 E. I. Dupont De Nemours And Company Structures surface modified with bidentate silanes
US5082559A (en) * 1989-08-25 1992-01-21 U.S. Philips Corporation Glass chromatography capillary with relatively thick coating
US5308495A (en) * 1990-01-23 1994-05-03 Yissum, Research Development Company Of The Hebrew University Of Jerusalem Chromatography processes using doped sol gel glasses as chromatographic media
US5224972A (en) * 1990-09-11 1993-07-06 Frye Gregory C Coatings with controlled porosity and chemical properties
US5338454A (en) * 1992-08-27 1994-08-16 Supelco, Incorporated Chiral mobile phase additives for improved liquid-chromatography separations
US5770084A (en) * 1995-01-01 1998-06-23 Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College Polymerized chiral micelles for chiral separations
US5886127A (en) * 1996-08-28 1999-03-23 University Of South Florida Combinatorial method of forming cascade polymer surfaces

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7947174B2 (en) 2000-02-09 2011-05-24 University Of South Florida Sol-gel monolithic column with optical window and method of making
US8597508B2 (en) 2000-02-09 2013-12-03 University Of South Florida Sol-gel monolithic column with optical window and method of making
US8685240B2 (en) 2001-03-09 2014-04-01 University Of South Florida High efficiency sol-gel gas chromatography column
US7244295B2 (en) * 2003-01-07 2007-07-17 The Research Foundation Of State University Of New York Hybrid anti-fouling coating compositions and methods for preventing the fouling of surfaces subjected to a marine environment
US7794795B2 (en) 2003-01-07 2010-09-14 The Research Foundation Of State University Of New York Hybrid anti-fouling coating compositions and methods for preventing the fouling of surfaces subjected to a marine environment
US10058843B2 (en) 2013-09-20 2018-08-28 Van So Le Multifunctional sorbent materials and uses thereof
CN109865315A (zh) * 2017-12-05 2019-06-11 中国科学院大连化学物理研究所 一种用作色谱固定相的有机-无机杂化介孔材料涂层制备方法
CN109876772A (zh) * 2019-04-22 2019-06-14 北京石油化工学院 纳米碳纤维与活性炭复合材料及其制备方法

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