Urea-functionalized sol-gel

Patent metadata

Field	Value
Publication number	US-11629235-B2
Application number	US-201916239615-A
Country	US
Kind code	B2
Filing date	Jan 4, 2019
Priority date	Jan 4, 2019
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

Urea and amine comprising sol-gel hybrid coatings have been developed for numerous applications, including capillary microextraction-high performance liquid chromatographic analysis from aqueous samples. A fused silica capillary may be coated from the inside with surface bonded coating material and may be created by in-situ sol-gel reaction(s). Urea-functionalized coatings can be immobilized on the inner surface of a capillary by condensing silanol groups of capillary and sol-solution. Urea functionalized, sol-gel coated capillaries may be installed, e.g., in HPLC manual injection ports, and optionally pre-concentrated analytes including phenols, ketones, aldehydes, and/or polyaromatic hydrocarbons, from highly polar to non-polar, maybe analyzed by online extraction and high-performance liquid chromatographic. Such coatings may achieve sensitivities with lower detection limits (S/N=3) of 0.10 ng/mL to 14.29 ng/mL, with reproducibilities of <12.0% RSD (n=3), or <10.0% RSD (n=3) by exchanging the capillary of the same size.

First claim

The invention claimed is:

1. A glass capillary-, comprising an inner surface and an outer surface,
wherein the inner surface comprises a coating comprising a sol-gel component HA comprising reacted units of:
a sol-gel precursor having a structure (I)
R′O 3 Si—(R′ 2 C) a —HN—C(═X)—NH—(CR′ 2 ) b —Si(OR′);  (I),

wherein X is 0 or S, R′ is independently H, methyl, ethyl, propyl, s-propyl, butyl, s-butyl, isobutyl, t-butyl, pentyl, s-pentyl, isoamyl, neopentyi, C6-alkyl, phenyl, or pyridyl, and a and b are independently in a range of from 1 to 20; and
a sol-gel active polymer having a structure (ii)
[HO—(HRC) m —] 2-y —H y N—(CHR) n —[—(SiR 2 —O) x —]—SiR 2 —(CHR) p —NH z —[(CHR) q —OH] 2-z   (II),

wherein R is independently H, methyl, ethyl, propyl, s-propyl, butyl, s-butyl, isobutyl, t-butyl, pentyl, s-pentyl, isoamyl, neopentyl, C6-alkyl, phenyl, or pyridyl, y and z are independently 0 or 1, x is in a range of from 5 to 2,500, and m, n, p, and q are independently in a range of from 1 to 20,
wherein the coating has a thickness in a range of from 1 to 10 microns, and
wherein the sol-gel component is covalently bonded to the inner surface of the glass capillary.

2. The glass capillary of claim 1 , wherein, in the sol-gel precursor, X is O, R′ is H, and a and b are in range of from 2 to 10.

3. The glass capillary of claim 2 , wherein, in the sol-gel precursor, a and b are identical and in a range of from 2 to 4.

4. The glass capillary of claim 1 , wherein, in the sol-gel active polymer, R is H, y and z are 0, x is in a range of from 25 to 500, and m, n, p, and q are independently in range of from 2 to 10.

5. The Mass capillary of claim 3 , wherein, in the sol-gel active polymer, R is H, y and z are 0, x is in a range of from 30 to 250, m and q are identical, and m, n, and p are independently in range of from 2 to 4.

6. The glass capillary of claim 4 , wherein, in the sol-gel active polymer, m and q are identical to each other, n and p are identical to each other, and m and n are independently in range of from 2 to 5.

7. The glass capillary of claim 1 , wherein the sol-gel component comprises termini comprising hydroxyalkyl groups.

8. The glass capillary of claim 1 , wherein a sol-gel reagent ratio, based on equivalents of the sol-gel polymer to equivalents of the sol-gel precursor, is in a range of from 1:1 to 1:5.

9. The glass capillary of claim 1 , which is formed in a solvent comprising an alcohol in at least 50 wt. % of total solvent weight.

10. The glass capillary of claim 1 , wherein at least 90% of the sol-gel precursor comprises bis(trimethoxysilylpropyl) urea, bis(triethoxysilylpropyl) urea, bis(trimethoxysilylethyl) urea, bis(triethoxysilylethyl) urea, bis(trimethoxysilylbutyl) urea, bis(triethoxysilylbutyl) urea, bis(trimethoxysilylmethylpropyl) urea, bis(triethoxysilylmethylpropyl) urea, bis(trimethoxysilylpentyl) urea, bis(triethoxysilylpentyl) urea, bis(trimethoxysilylhexyl) urea, bis(triethoxysilylhexyl) urea, bis(trimethoxysilylcyclohexyl) urea, and/or bis(triethoxysilylcyclohexyl) urea, and
wherein at least 90% of the sol-gel active polymer comprises
[HO—(H 2 C) 2 ] 2 —N—(CH 2 ) 2 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 2 —N[(CH 2 ) 2 OH] 2 ,
[HO—(H 2 C) 3 ] 2 —N—(CH 2 ) 2 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 2 —N[(CH 2 ) 3 OH] 2 ,
[HO—(H 2 C) 2 ] 2 —N—(CH 2 ) 3 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 3 —N[(CH 2 ) 2 OH] 2 ,
[HO—(H 2 C) 3 ] 2 —N—(CH 2 ) 3 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 3 —N[(CH 2 ) 3 OH] 2 ,
[HO—(H 2 C) 2 ] 2 —N—(CH 2 ) 4 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 2 —N[(CH 2 ) 2 OH] 2 ,
[HO—(H 2 C) 4 ] 2 —N—(CH 2 ) 2 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 2 —N[(CH 2 ) 4 OH] 2 ,
[HO—(H 2 C) 3 ] 2 —N—(CH 2 ) 4 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 4 —N[(CH 2 ) 3 OH] 2 ,
[HO—(H 2 C) 4 ] 2 —N—(CH 2 )—[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 2 ) 2 —(CH 2 ) 3 —N[(CH 2 ) 4 OH] 2 , and/or
[HO—(H 2 C) 4 ] 2 —N—(CH 2 ) 4 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 4 —N[(CH 2 ) 4 OH] 2 .

11. The glass capillary of claim 1 , wherein the coating is formed by reacting bis(trimethoxysilylpropyl)urea (BPU) and [bis(hydroxyethyl)amine] (BHEA)-terminated polydimethylsiloxane.

12. The glass capillary of claim 7 , comprising
a glass surface comprising silanol moieties; and
the sol-gel component,
wherein terminal hydroxyl groups of the sol-gel are condensed with the silanol moieties of the glass surface to form a covalent bond.

13. The glass capillary of claim 1 , which is a fused silica micro-extraction capillary.

14. The glass capillary of claim 13 , wherein the fused silica micro-extraction capillary comprises a Type I fused silica.

15. A micro extraction method, comprising:
(a) introducing an aqueous sample into the glass capillary of claim 1 ; and optionally
(b) passing an eluant comprising acetonitrile and/or deionized water through the glass capillary.

16. A method for analyzing a sample, the method comprising:
(a) introducing a dissolved sample into the glass capillary of claim 1 ;
(b) passing an eluant through the glass capillary;
(c) desorbing an extracted analyte from the glass capillary onto an analytical column; and
(d) eluting the analytical column.

17. A method of enhancing analytical sensitivity, the method comprising:
combining the glass capillary of claim 1 in series with an HPLC or GC column.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Alhooshani Khalid R
• Jilani Shehzada Muhammad Sajid

Classifications

• C08J3/075 Primary

  Macromolecular gels · CPC title

• B01J13/0039

  Post treatment · CPC title

• C03C17/30

  with silicon-containing compounds · CPC title

• C03C17/32

  with synthetic or natural resins (C03C17/30 takes precedence) · CPC title

• C08G77/26

  nitrogen-containing groups · CPC title