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.

Abstract: Yttria containing hybrid organic-inorganic sol-gels may be used in coatings for capillary microextraction, optionally hyphenated to online HPLC analysis. The sol-gel reaction mixture can use an yttrium trialkoxyalkoxide, such as yttrium trimethoxyethoxide, and a [bis(hydroxyalkyl)-amino-alkyl]-terminated polydialkyl/arylsiloxane, such as [bis(hydroxyethyl)-amine] (BHEA)-terminated polydimethylsiloxane, that can undergo hydrolysis and polycondensation, to form coating materials. Capillaries coated with such sol-gels can have improved extraction efficiency compared, e.g., to pure yttria-based coatings. The CME-HPLC can analyze water samples containing analytes of varied polarity, with excellent extraction of amides, phenols, alcohols, ketones, aldehydes, and polyaromatic hydrocarbons and detection limits ranging from 0.18 to 7.35 ng/mL (S/N=3). Such capillaries can exhibit solvent stability at pH 0 to 14, RSD % between 0.6 to 6.8% (n=3), at a preparative reproducibility RSD between 4.1 and 9.9%.

Abstract: Yttria containing hybrid organic-inorganic sol-gels may be used in coatings for capillary microextraction, optionally hyphenated to online HPLC analysis. The sol-gel reaction mixture can use an yttrium trialkoxyalkoxide, such as yttrium trimethoxyethoxide, and a [bis(hydroxyalkyl)-amino-alkyl]-terminated polydialkyl/arylsiloxane, such as [bis(hydroxyethyl)-amine] (BHEA)-terminated polydimethylsiloxane, that can undergo hydrolysis and polycondensation, to form coating materials. Capillaries coated with such sol-gels can have improved extraction efficiency compared, e.g., to pure yttria-based coatings. The CME-HPLC can analyze water samples containing analytes of varied polarity, with excellent extraction of amides, phenols, alcohols, ketones, aldehydes, and polyaromatic hydrocarbons and detection limits ranging from 0.18 to 7.35 ng/mL (S/N=3). Such capillaries can exhibit solvent stability at pH 0 to 14, RSD % between 0.6 to 6.8% (n=3), at a preparative reproducibility RSD between 4.1 and 9.9%.

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.