Urea-functionalized sol-gel

Patent metadata

Field	Value
Publication number	US-2020216620-A1
Application number	US-201916239615-A
Country	US
Kind code	A1
Filing date	Jan 4, 2019
Priority date	Jan 4, 2019
Publication date	Jul 9, 2020
Grant date	—

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

1 : A capillary, comprising an inner surface and an outer surface,
wherein the inner surface comprises a coating comprising sol-gel, comprising, in reacted form: 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′) 3   (I),

wherein X is O or S, 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, 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.

2 : The 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 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 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 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 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 capillary of claim 1 , wherein the sol-gel precursor is pre-condensed before condensation with the sol-gel active polymer.

8 : The capillary of claim 7 , wherein the sol-gel precursor is pre-condensed with a chelating agent comprising acetic acid, citric acid, malonic acid, oxalic acid, trifluoroacetic acid, methanesulfonic acid, toluenesulfonic acid, benzenesulfonic acid, triflic acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, and/or sulfuric acid, in at least 75 wt. %, based on total chelating agent weight.

9 : The capillary of claim 1 , wherein the chelating agent has a pK a of less than 1.

10 : The capillary of claim 1 , comprising termini comprising hydroxyalkyl groups.

11 : The 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.

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

13 : The 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 ) 20 H] 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 ) 30 H] 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 ) 20 H] 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 ) 30 H] 2 , [HO—(H 2 C) 2 ] 2 —N—(CH 2 ) 4 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 4 —N[(CH 2 ) 20 H] 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 ) 40 H] 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 ) 30 H] 2 , [HO—(H 2 C) 4 ] 2 —N—(CH 2 ) 3 —[—(Si(CH 3 ) 2 —O) 30-50 ]—Si(CH 3 ) 2 —(CH 2 ) 3 —N[(CH 2 ) 40 H] 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 ) 40 H] 2 .

14 : The capillary of claim 1 , formed by reacting bis(trimethoxysilylpropyl)urea (BPU) and [bis(hydroxyethyl)amine] (BHEA)-terminated poly dimethylsiloxane.

15 : The capillary of claim 1 , comprising
a glass surface comprising silanol moieties; and the sol-gel, wherein terminal hydroxyl groups of the sol-gel active polymer are condensed with the silanol moieties of the glass surface to form a covalent bond having the substructure [glass]-Si—[O—(HRC) m —] 2-y —H y N—(CHR) n —[—(SiR 2 —O) x —] . . . .

16 : The capillary of claim 1 , which is a fused silica micro-extraction capillary.

17 : The capillary of claim 16 , wherein the fused silica micro-extraction capillary comprises a Type I fused silica.

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

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

20 : A method of enhancing analytical sensitivity, the method comprising:
combining the 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

• C03C17/004

  Coating the inside · CPC title

• C09D183/08

  containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen · CPC title

• C08G77/26

  nitrogen-containing groups · CPC title

• C03C17/30

  with silicon-containing compounds · CPC title

• C03C2218/113

  by sol-gel processes · CPC title