Superpolar chromatographic stationary phases and extraction sorbents and their methods of synthesis

Abstract

A superpolar sorbent network is a sol-gel network of at least one metal oxide precursor condensed and at least one polyhydroxy molecule. The metal oxide precursor is a silicate precursor, aluminate precursor, titanate precursor, zirconate precursor, germinate precursor, or any combinations thereof, and the polyhydroxy molecule has a multiplicity of hydroxyl groups. The polyhydroxy molecule can be an organic molecule derived from nature. The superpolar sorbent network can be used as a particulate or bulk sorbent for sampling or removal of analytes or contaminants from an environment or can be coated on a tube or particulate substrate for use as a chromatographic stationary phase.

Claims

1. A superpolar sorbent network, comprising a sol-gel network of at least one metal oxide precursor condensed with at least one polyhydroxy molecule where the network comprises units with metal-oxygen-metal groups and units with metal-oxygen-carbon groups respectively bonded to the at least one polyhydroxy molecule of one or more of the structures: ##STR00001## where there is a random placement of units within the network, where units from tetraalkoxysilanes are 0-100 weight percent of the network, where units from trialkoxysilanes are 0 to 100 weight percent of the network, and optionally comprising units from dialkoxysilanes at 0 to 99 weight percent of the network, where the polyhydroxy molecule has differing patterns and degrees of condensation, where optionally, the silicon-oxygen-silicon groups and the silicon-oxygen-carbons groups of the structure are replaced with metal-oxygen-metal groups and metal-oxygen-carbon groups of another metal where the another metal is aluminum, titanium, zirconium, or germanium from at least one aluminate precursor, titanate precursor, zirconate precursor, or germinate precursor, and where, optionally, the polyhydroxy units from sucrose are replaced with the polyhydroxy units of an another organic molecule comprising a multiplicity of hydroxyl groups.

2. The superpolar sorbent network according to claim 1, wherein the metal oxide precursor is a tetraalkoxysilane, trialkoxysilane, or a combination of at least one of the tetraalkoxysilane and trialkoxysilane with a dialkoxysilane.

3. The superpolar sorbent network according to claim 1, wherein the another organic molecule is Sucrose-6-phosphate, Sucrose6F-phosphate, 2-Cyanoethylsucrose, Sucralose, 1-Ketose, UDP-alpha-D-glucose, Uridine Diphosphate Glucose, Sorbitol, or any mixture thereof.

4. The superpolar sorbent network according to claim 1, wherein the metal oxide precursor is tetramethoxysilane and the polyhydroxy molecule comprises sucrose.

5. The superpolar sorbent network according to claim 1, wherein the metal oxide precursor is methyltrimethoxysilane and the polyhydroxy molecule comprises sucrose.

6. The superpolar sorbent network according to claim 1, wherein the at least one metal oxide precursor includes an unsubstituted or substituted arytrialkoxysilane.

7. The superpolar sorbent network according to claim 1, wherein the at least one metal oxide precursor includes an unsubstituted or substituted alkyltrialkoxysilane.

8. A sampling device or analytical device comprising a superpolar sorbent network according to claim 1, wherein the sampling device is an extraction device or a chromatography device.

9. The sampling device or analytical device according to claim 8, wherein the extraction device is a fiber superpolar microextraction fiber, superpolar microextraction tube, superpolar microextraction membrane, superpolar microextraction stir bar, superpolar microextraction fabric, superpolar microextraction capsule, or superpolar microextraction vial.

10. The sampling device or analytical device according to claim 8, wherein the extraction device is a solid phase extractor selected from a matrix solid phase dispersant, a magnetic solid phase extractor, or a dynamic fabric phase sorptive extractor.

11. The sampling device or analytical device according to claim 8, wherein the analytical device is a gas chromatograph or a liquid chromatograph.

12. A method of preparing a superpolar sorbent network according to claim 1, comprising: providing at least one metal oxide precursor; providing at least one polyhydroxy molecule; providing water; providing a catalyst; optionally, providing a solvent; combining the at least one metal oxide precursor, the at least one polyhydroxy molecule, the water, the catalyst, and, optionally, the solvent to form a sol; hydrolyzing the sol, wherein the at least one metal oxide precursors form hydrolyzed metal oxide precursors; and condensing the hydrolyzed metal oxide precursors and the at least one polyhydroxy molecules to form a gel that provides the superpolar sorbent network.

13. The method according to claim 12, wherein condensing occurs with heating of the sol.

14. The method according to claim 12, further comprising coating the sol on a substrate, wherein the superpolar sorbent network comprises a coating on the substrate.

15. The method according to claim 14, wherein the substrate is a metal oxide particle, a metal tube, a silica fiber, a fabric, a glass tube, a glass sheet, or a vial.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1A is a reaction scheme for the formation of a superpolar sorbent network, according to an embodiment of the invention.

(2) FIG. 1B are chemical structures of polyhydroxy molecules that can be used for the formation of the superpolar sorbent network, according to an embodiment of the invention, where HOR.sub.2OH is the polyhydroxy molecule used for formation of the superpolar sorbent network.

(3) FIG. 2 shows some exemplary structures of superpolar sorbent networks that are formed from sucrose and various tetraalkoxysilanes and trialkoxysilanes to permit various interactions for the absorption of analytes, according to embodiments of the invention.

(4) FIG. 3 is a bar chart of the extraction of various analytes using a sol-gel tetramethoxysilane and sucrose superpolar sorbent, according to an embodiment of the invention, and a sol-gel polydimethylsiloxane sorbent, where the difference in heights of the bars reflects the selectivity for the analyte.

(5) FIG. 4A displays a chart of microextraction sorbent devices, according to an embodiment of the invention, which can be fabricated using the superpolar sorbent networks.

(6) FIG. 4B displays a chart of solid phase extraction devices, according to an embodiment of the invention, which can be fabricated using the superpolar sorbent networks.

(7) FIG. 4C displays a chart of chromatographic stationary phases for analytical devices, according to an embodiment of the invention, which can be fabricated using the superpolar sorbent networks

DETAILED DISCLOSURE

(8) Embodiments of the invention are directed to superpolar sorbent networks that can be employed as coatings or bulk resins for use as highly polar chromatographic stationary phases and adsorption sorbents. These superpolar sorbent networks are metal oxide-organic hybrids including sol-gel networks that comprise sucrose, ketose, uridine diphosphate glucose, or other highly polar polyhydroxy molecules. The polyhydroxy molecule can be derived from natural materials or can be synthetic molecules, such as oligomers of vinyl alcohol. These highly polar polyhydroxy molecules are immobilized via sol-gel process on the substrate. This sol-gel coating can be on the inside a fused silica capillary for use as a gas chromatographic stationary phase or as an in-tube solid phase microextractor. This sol-gel coating can be on the outside of a fused silica fiber or a metal rod for use as a solid phase microextraction sorbent. This sol-gel coating can be on the surface of silica, alumina, titania, zirconia, germania, or other metal oxide particles for use as liquid chromatographic stationary phase. This sol-gel resin can be prepared in-situ as a monolithic bed inside a wide bore tube for use as a liquid chromatographic stationary phase. Different shapes, sizes and geometries can be fabricated that are well suited to function as solid phase extraction sorbent particles as required of the final application and delivery mechanism. A sol solution can be a homogenous mixture or a dispersion that additionally can include at least one sol-gel precursor that is capable of providing London dispersion type forces and/or at least one sol-gel precursor capable of exerting pi-pi interaction with target analytes. The new sorbents and chromatographic stationary phases formed from the coatings, according to embodiments of the invention, interact with various target analytes via one or more dipole-dipole interactions, hydrogen bonding, London dispersion forces, and pi-pi interactions.

(9) In an embodiment of the invention, the high polarity of sucrose and/or other polar polyhydroxy molecules with various molecular interaction mechanisms can be incorporated into a polymeric network via sol-gel processing in a simple, highly reproducible, and environmentally benign manner. The highly polar chromatographic stationary phases and adsorption sorbents, for solid phase extraction (exhaustive extraction) or solid phase microextraction (equilibrium driven extraction), can be effectively employed to absorb or analyze polar, medium polar, nonpolar, and polarizable analytes. Examples of the highly polar polyhydroxy molecules that can be incorporated into the sol-gel coating are given in Table 1, below. These molecules can be combined with metal oxide precursors into a sol or partially hydrolyzed and condensed sol to form a composite sol that can be applied to a substrate surface. The use of the small molecules and oligomers have advantages over typical organic polymers that are large and have varying degrees of polydispersity resulting in relatively poor batch-to-batch reproducibly. This reproducibility issue can be largely addressed by using relatively monodispersed polymers and dendrimers, as taught in Kabir, A., et al. Capillary Microextraction on Sol-Gel Dendrimer Coatings. Journal of Chromatography A 2004, 1034(1-2), 1-11, yet such monodispersed polymers are often expensive to employ. The use of monomeric, dimeric, or small oligomeric organic molecules, having relatively fixed molecular weights, optimizes batch-to-batch reproducibility. These organic molecules can also be converted into organically modified inorganic precursors to enhance reaction selectivity for formation of composite material.

(10) TABLE-US-00001 TABLE 1 Exemplary polyhydroxy molecules for formation of sols that are converted into metal oxide-organic hybrid sorbents Monomer MW Empirical Formula Log K.sub.ow Ethylene glycol 62.06 C.sub.4H.sub.10O.sub.4 1.4 Sucrose 342.30 C.sub.12H.sub.22O.sub.11 3.7 Sucrose-6-phosphate 422.28 C.sub.12H.sub.23O.sub.14P 5.3 Sucrose-6F-phosphate 420.26 C.sub.12H.sub.21O.sub.14P.sup.2 5.5 2-Cyanoethyl sucrose 395.36 C.sub.15H.sub.25NO.sub.11 4.0 Sucralose 397.63 C.sub.12H.sub.19C.sub.13O.sub.8 1.5 1-Ketose 504.44 C.sub.18H.sub.32O.sub.16 5.5 UDP-alpha-D-glucose 564.29 C.sub.15H.sub.22N.sub.2O.sub.17P.sub.2.sup.2 6.5 Uridine Diphosphate Glucose 566.30 C.sub.15H.sub.24N.sub.2O.sub.17P.sub.2 6.3 Sorbitol 182.17 C.sub.6H.sub.14O.sub.6 3.1

(11) The metal oxide precursors for inclusion in the sol can be selected from precursors for silicates, aluminates, titanates, zirconates, germinates, other metal oxide precursors, or any mixture thereof. The nature of the metal oxide precursors is herein exemplified by silanes, but the equivalent with other metals and number of substituents can be readily appreciated by practitioners of the art. For silicate based superpolar sorbents, the precursors can be a combination of tetraalkoxysilanes, trialkoxysilanes, and dialkoxysilanes. The proportion of tetraalkoxysilanes can be 0-100 weight percent. The proportion of triakoxysilanes can be 0 to 100 weight percent. The proportion of dialkoxysilanes can be 0 to 99 weight percent.

(12) Tetraalkoxysilanes, can be, but are not limited to, tetramethoxysilane and tetraethoxysilane. Tetraalkoxysilanes can be used exclusively with the polar organic molecules or with mixtures of trialkoxysilanes or dialkoxysilanes. The trialkoxysilanes can be, but are not limited to, alkyltrialkoxysilanes, such as methyltrimethoxysilanes, ethyltrimethoxysilanes, methyltriethoxysilanes, ethyltrialkoxysilanes, or any C.sub.xH.sub.2x+1Si(OC.sub.yH.sub.2y+1).sub.3 silane, where x is 1 to 20 and y is 1 to 3. The alkyltrialkoxy silane can have a substituted alkyl group, for example, but not limited to, 3-aminoporpyltrimethoxysilane, 2-aminopropyltrimethoxysilane, 3-hydroxytrimethoxysilane, or any alkyl group containing one or more ether, hydroxyl, carboxylic acid, carboxylic amide, amino, alkylamino, dialkylamino, cyano group, or any other polar or non-polar groups. The trialkoxysilanes can be aryltrialkoxysilanes, such as, but not limited to, phenyltrimethoxysilane, phenyltriethoxysilane, naphtyltrimethoxysilane, naphtyltriethoxysilane, or any other substituted or unsubstituted aryl trialkoxysilane.

(13) The dialkoxysilanes can be dialkyldialkoxysilanes, diaryldialkoxysilane, or alkylarydialkoxysilanes. Dialkyldialkoxysilanes can be, for example, but not limited to, dimethyldimethoxiysilanes, diethyldimethoxysiloxanes, methylethyldimethoxysilanes, dimethyldiethoxiysilanes, diethyldiethoxysiloxanes, methylethyldiethoxysilanes, or any (C.sub.xH.sub.2x+1).sub.2Si(OC.sub.yH.sub.2y+1).sub.2 silane, where x is independently 1 to 20 and y is 1 to 3. The dialkyldialkoxyslanes can have one or two substituted alkyl groups, where the alkyl group contains one or more ether, hydroxyl, carboxylic acid, carboxylic amide, amino, alkylamino, dialkylamino, cyano group, or any other polar or non-polar group.

(14) The superpolar sorbent is prepared by the condensation of the silanes with a molecule that has multiple hydroxyl groups attached to a hydrocarbon framework, a polyhydroxy molecule. The condensation is carried out in the presences of water, where the proportion of water to alkoxy groups of the tetraalkoxysilanes, trialkoxysilanes, and dialkoxysilanes is less than one to two, such as those shown in Table 1. The molecules with multiple hydroxyl groups have a log K.sub.ow, the partitioning coefficient between octanol and water, as indicated in Table 1, having a log K.sub.ow, for example, less than 2 is useful for superpolar sorbent preparation.

(15) In an embodiment of the invention, the superpolar sorbent is prepared by an acid catalyzed hydrolysis and condensation of the silanes in the presence of water and the polyhydroxy molecules, as illustrated in FIG. 1A with exemplary polyhydroxy molecules of Table 1, illustrated in FIG. 1B. The acid can be a Bronsted acid such as trifluoroacetic acid (TFA), as shown in FIG. 1A, or any strong acid, such as hydrochloric acid, sulfuric acid, or hydrofluoric acid. A solvent, for example ethanol, or any polar organic solvent, for example, but not limited to dimethylsulfoxide (DMSO), methylene chloride, chloroform, or methanol, can be included in the sol. The sol is prepared and either further condensed into a particle form or a substrate, which can be particulate, fabric or of any structure, can be contacted with the sol solution. Contact can be by suspension of the substrate in the sol, painting the substrate with the sol, or spraying the substrate with the sol. The sol is finally condensed into a network. In another embodiment of the invention, the catalysis can be by base rather than acid. Base catalysts can be sodium hydroxide, potassium hydroxide, or amine, such as pyridine, trimethylamine, or ammonia.

(16) The superpolar sorbent network can have various structures that form interactions with the substrate molecules, in addition to the dipole-dipole interactions, which include hydrogen bonding interactions, ion-dipole interactions, or ion-pairing interactions, for purposes of the invention, that are provided by the incorporation of the polyhydroxy molecules with a tetralkoxysilane derived network, by choice of the trialkoxysilanes and dialkoxysilanes employed, groups that can also interact by London dispersion forces, - interactions, and additional dipole-dipole, ion-dipole, or ion pairing interactions can be included. Various combinations are illustrated by structures employing sucrose in FIG. 2. These idealized structures of FIG. 2 do not show the random placement of units within the network, uncondensed silanols that form upon hydrolysis but are not condensed, unhydrolyzed alkoxysilane bonds, nor are the various possibilities of differing patterns and degrees of condensation of the sucrose illustrated in FIG. 2. It is to be understood that these structures only illustrate the types of units within exemplary networks.

(17) Fields of study such as: metabolomics; environmental chemistry; analytical and forensic toxicology; clinical chemistry; drug discovery; and food quality and safety monitoring must deal with highly polar analytes present in a variety of sample matrices with high volume of matrix interferents. Due to the strong interactions between water molecules and polar analytes, it is extremely difficult to break these water-polar analyte interactions in order to isolate and concentrate them into a solid sorbent for subsequent instrumental analysis. The lack of highly polar sorbents has seriously impaired the advancement of these fields. Highly sensitive analytical instruments complemented with powerful operating software have not resolved problems originating from sample preparation difficulties. The superpolar sorbents could overcome inabilities due to limitations of sample preparation techniques, and replace a large number of ineffective materials currently being used as polar sorbents. For example, the United States Environmental Protection Agency (EPA) has a priority list of compounds where monitoring and detection are important. As can be seen in Table 2, below, one third of the top 100 chemicals on this list have a K.sub.ow of about 2 or less, which suggests the use of the superpolar sorbents.

(18) TABLE-US-00002 TABLE 2 Top 100 EPA Priority Pollutants Molecular H Bond H Bond Compound Weight Formula Log K.sub.ow Donor Acceptor Acenaphthene 154.207 C.sub.12H.sub.10 3.9 0 0 Acrolein 56.063 C.sub.3H.sub.4O 0.01 0 1 Acrylonitrile 53.062 C.sub.3H.sub.3N 0.25 0 1 Benzene 78.111 C.sub.6H.sub.6 2.1 0 0 Benzidine 184.237 C.sub.12H.sub.12N.sub.2 1.34 2 2 Carbon tetrachloride 153.823 CCl.sub.4 2.83 0 0 Chlorobenzene 112.557 C.sub.6H.sub.5Cl 2.84 0 0 1,2,4-Trichlorobenzene 181.4470 C.sub.6H.sub.3Cl.sub.3 4.02 0 0 Hexachlorobenzene 284.7822 C.sub.6Cl.sub.6 5.7 0 0 1,2-Dichloroethane 98.9592 C.sub.2H.sub.4Cl.sub.2 1.5 0 0 1,1,1-Trichloroethane 133.4042 C.sub.2H.sub.3Cl.sub.3 2.4 0 0 Hexachloroethane 236.7394 C.sub.2Cl.sub.6 4.1 0 0 1,1-Dichloroethane 98.9592 C.sub.2H.sub.4Cl.sub.2 1.5 0 0 1,1,2-Trichloroethane 133.4042 C.sub.2H.sub.3Cl.sub.3 2.4 0 0 1,1,2,2-Tetrachloroethane 167.8493 C.sub.2H.sub.2Cl.sub.4 2.4 0 0 Chloroethane 64.5141 C.sub.2H.sub.5Cl 1.2 0 0 Bis(2-Chloroethyl)ether 143.0117 C.sub.4H.sub.8Cl.sub.2O 1.3 0 1 2-Chroethyl vinyl ether 106.5508 C.sub.4H.sub.7ClO 1.4 0 1 2-Chloronaphthalene 162.6156 C.sub.10H.sub.7Cl 4.1 0 0 2,4,6-Trichlorophenol 197.4464 C.sub.6H.sub.3Cl.sub.3O 3.7 1 1 Parachlorometacresol 142.5829 C.sub.7H.sub.7ClO 3.1 1 1 Chloroform 119.3776 CHCl.sub.3 2.3 0 0 2-Chlorophenol 128.5563 C.sub.6H.sub.5ClO 2.1 1 1 1,2-Dichlorobenzene 147.0020 C.sub.6H.sub.4Cl.sub.2 3.4 0 0 1,3-Dichlorobenzene 147.0020 C.sub.6H.sub.4Cl.sub.2 3.5 0 0 1,4-Dichlorobenzene 147.0020 C6H.sub.4Cl.sub.2 3.4 0 0 3,3-Dichlorobenzidine 253.1272 C.sub.12H.sub.10Cl.sub.2N.sub.2 3.5 2 2 1,1-Dichloroethylene 96.9434 C.sub.2H.sub.2Cl.sub.2 2.3 0 0 1,2-Transdichloroethylene 96.9434 C.sub.2H.sub.2Cl.sub.2 1.9 0 0 2,4-Dichlorophenol 163.0014 C.sub.6H.sub.4Cl.sub.2O 3.1 1 1 1,2-Dichloropropane 112.9857 C.sub.3H.sub.6Cl.sub.2 1.8 0 0 1,3-Dichloropropylene 110.9699 C.sub.3H.sub.4Cl.sub.2 1.7 0 0 2,4-Dimethylphenol 122.1644 C.sub.8H.sub.10O 2.3 1 1 2,4-Dinitrotoluene 182.1335 C.sub.7H.sub.6N.sub.2O.sub.4 2 0 4 2,6-Dinitrotoluene 182.1335 C.sub.7H.sub.6N.sub.2O.sub.4 2.1 0 4 1,2-Diphenylhydrazine 184.1335 C.sub.12H.sub.12N.sub.2 2.9 2 2 Ethylbenzene 202.2506 C.sub.8H.sub.10 3.1 0 0 Fluoranthene 202.2506 C.sub.16H.sub.10 5.2 0 0 4-Chlorophenyl phenyl ether 204.6523 C.sub.12H.sub.9ClO 4.3 0 1 4-Bromophenyl phenyl ether 249.1033 C.sub.12H.sub.9BrO 4.4 0 1 Bis(2-Chloroisopropyl)ether 171.0649 C.sub.6H.sub.12Cl.sub.2O 2.7 0 1 Bis(2-Chloroethoxy)methane 173.0377 C.sub.5H.sub.10Cl.sub.2O.sub.2 1.2 0 2 Methylene Chloride 84.9426 CH.sub.2Cl.sub.2 1.5 0 0 Methyl chloride 50.4875 CH3Cl 0.8 0 0 Methyl bromide 94.9385 CH.sub.3Br 1 0 0 Bromoform 252.7306 CHBr.sub.3 2.8 0 0 Dichlorobromomethane 163.8286 CHBrCl.sub.2 2.4 0 0 Chlorodibromomethane 208.2796 CHBr.sub.2Cl 2.6 0 0 Hexachlorobutadiene 260.7608 C.sub.4Cl.sub.6 4.8 0 0 Hexachlorocyclopentadiene 272.7715 C.sub.5Cl.sub.6 5 0 0 Isophorone 138.2069 C.sub.9H.sub.14O 1.6 0 1 Naphthalene 128.1705 C10H8 3.3 0 0 Nitrobenzene 123.1094 C.sub.6H.sub.5NO.sub.2 1.9 0 2 2-Nitrophenol 139.1088 C.sub.6H.sub.5NO.sub.3 1.8 1 3 4-Nitrophenol 139.1088 C.sub.6H.sub.5NO.sub.3 1.9 1 3 2,4-Dinitrophenol 184.1064 C.sub.6H.sub.4N.sub.2O.sub.5 1.7 1 5 4,6-Dinitro-o-cresol 198.1329 C.sub.7H.sub.6N.sub.2O.sub.5 2.1 1 5 N-Nitrosodimethylamine 74.0818 C.sub.2H.sub.6N.sub.2O 0.6 0 3 N-Nitrosodiphenylamine 198.2206 C.sub.12H.sub.10N.sub.2O 3.1 0 3 N-Nitrosodi-n-propylamine 130.1881 C.sub.6N.sub.14N.sub.2O 1.4 0 3 Pentachlorophenol 266.3365 C.sub.6HCl.sub.5O 5.1 1 1 Phenol 94.1112 C.sub.6H.sub.6O 1.5 1 1 Bis(2-Ethylhexyl)phthalate 390.5561 C.sub.24H.sub.38O.sub.4 7.4 0 4 Butyl benzyl phthalate 312.3597 C.sub.19H.sub.20O.sub.4 4.9 0 4 Di-N-butyl phthalate 278.3435 C.sub.16H.sub.22O.sub.4 4.7 0 4 Di-n-octyl phthalate 390.5561 C.sub.24H.sub.38O.sub.4 9.1 0 4 Diethyl phthalate 222.2372 C.sub.12H.sub.14O.sub.4 2.5 0 4 Dimethyl phthalate 194.1841 C.sub.10H.sub.10O.sub.4 1.6 0 4 Benzo(a)anthracene 228.2879 C.sub.18H.sub.12 5.8 0 0 Benzo(a)pyrene 252.3093 C.sub.20H.sub.12 6 0 0 Benzo(b)fluoranthene 252.3093 C.sub.20H.sub.12 6.4 0 0 Benzo(k)fluoranthene 252.3093 C.sub.20H.sub.12 6.4 0 0 Chrysene 228.2879 C.sub.18H.sub.12 5.7 0 0 Acenaphthylene 152.1919 C.sub.12H.sub.8 3.7 0 0 Anthracene 178.2292 C.sub.14H.sub.10 4.4 0 0 Benzo(ghi)perylene 276.33 C.sub.22H.sub.12 6.6 0 0 Fluorene 166.2185 C.sub.13H.sub.10 4.2 0 0 Phenanthrene 178.2292 C.sub.14H.sub.10 4.5 0 0 Dibenzo(h)anthracene 278.3466 C.sub.22H.sub.14 6.5 0 0 Indeno (1,2,3-cd) pyrene 276.3307 C.sub.22H.sub.12 7 0 0 Pyrene 202.2506 C.sub.16H.sub.10 4.9 0 0 Tetrachloroethylene 165.8334 C.sub.2C.sub.14 3.4 0 0 Toluene 92.1384 C.sub.7H.sub.8 2.7 0 0 Trichloroethylene 131.3883 C.sub.2HCl.sub.3 2.6 0 0 Vinyl chloride 62.4982 C.sub.2H.sub.3Cl 1.5 0 0 Aldrine 364.9099 C.sub.12H.sub.8Cl.sub.6 4.5 0 0 Dieldrin 380.9093 C.sub.12H.sub.8C.sub.16O 3.7 0 1 Chlordane 409.7786 C.sub.10H.sub.6Cl.sub.8 4.9 0 0 4,4-DDT 354.4863 C.sub.14H.sub.9Cl.sub.5 6.9 0 0 4,4-DDE 318.0253 C.sub.14H.sub.8Cl.sub.4 7 0 0 4,4-DDD 320.0412 C.sub.14H.sub.10Cl.sub.4 6.2 0 0 Alpha-endosulfan 406.9251 C.sub.9H.sub.6Cl.sub.6O.sub.3S 3.8 0 4 Beta-endosulfan 406.9251 C.sub.9H.sub.6Cl.sub.6O.sub.3S 3.8 0 4 Endosulfan sulfate 422.9245 C.sub.9H.sub.6Cl.sub.6O.sub.4S 3.7 0 4 Endrin 380.9093 C.sub.12H.sub.8Cl.sub.6O 3.7 0 1 Endrin aldehyde 380.9093 C.sub.12H.sub.8Cl.sub.6O 3 0 1 Heptachlor 373.3177 C.sub.10H.sub.5Cl.sub.7 4.3 0 0 Heptachlor epoxide 389.3171 C.sub.10H.sub.5Cl.sub.7O 3.7 0 1 Alpha-BHC 290.8298 C.sub.6H.sub.6Cl.sub.6 3.8 0 0

(19) The superpolar sorbents, according to embodiments of the invention, are effective at the absorption of polar compounds. For example, the exemplary superpolar sorbent prepared from sucrose and poly(dimethylsiloxane) are compared in FIG. 3, with a variety of analytes that have log K.sub.ow having superior absorption in the superpolar sorbent than in the non-polar solvent. The superiority of the sol-gel sucrose derived superpolar sorbent was observed for every analyte with the exception of the analyte naphthalene.

(20) The superpolar sorbents can be used in a wide variety of applications. The superpolar absorbents can be coated onto microextraction devices, as indicated in FIG. 4A. The superpolar sorbents can be used for exhaustive extraction, as indicated in FIG. 4B. The superpolar sorbents can be used for stationary phases for chromatographic separation of analytes in a mixture, as indicated in FIG. 4C.

METHODS AND MATERIALS

(21) Superpolar Sol-Gel Sucrose Sorbent Composition Preparation

(22) Sol-Gel Sucrose for a Monolithic Bed or SPE Particles:

(23) A sol was prepared from sucrose (1.00 g), tetramethoxysilane (TMOS) (1000 L), and 0.1M HF solution (2000 L) in ethanol (5000 L). The sol solution ingredients were mixed using a vortex stirrer, and subsequently held still at 50 C., whereupon gelation occurred.

(24) Sol-Gel Sucrose for Thin Film Generation on a Substrate Surface:

(25) A sol was prepared from sucrose (1.00 g), methyltrimethoxysilane (MTMOS) (2.5 mL), and 0.1M 5% aqueous TFA solution (1 mL) in DMSO (5 mL). After thoroughly mixing the sol solution ingredients using a vortex mixer a substrate for sol-gel coating was submerged into the sol solution and the coating unit was kept at 50 C.

(26) All publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

(27) It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.