A nanoliquid chromatographic method for the stereoisomer separation of some flavanone aglycones and 7-O-glycosides has been proposed employing a C18 capillary column and a chiral mobile-phase additive such as cyclodextrin. The chiral separation of eriodictyol, naringenin, and hesperitin was obtained by addition of carboxymethyl-β-cyclodextrin to the mobile phase, whereas eriocitrin, naringin, narirutin, and hesperidin diastereoisomers were resolved by using sulfobutyl ether-β-cyclodextrin. The influence of the composition of the mobile phase, the length of the capillary column, and the flow rate on the chiral recognition were investigated. At optimum conditions, baseline separation for the selected aglycones and glycosylated forms were achieved with a mobile phase consisting of 50 mM sodium acetate buffer pH 3 and 30% methanol containing 20 mM of carboxymethyl-β-cyclodextrin and 10 mM of sulfobutyl ether-β-cyclodextrin, respectively. Precision, linearity, and sensitivity of the method were tested. Limits of detection and quantification for the studied flavanone glycosides were in the range 1.3-2.5 and 7.5-12.5 µg/mL, respectively. The method was used for the determination of the diastereomeric composition of the flavanone-7-O-glycosides in Citrus juices after solid-phase extraction procedure.
- Klíčová slova
- chiral mobile phase additive, citrus juices, cyclodextrins, nano-liquid chromatography, stereoisomer separation,
- MeSH
- beta-cyklodextriny chemie MeSH
- flavanony chemie izolace a purifikace MeSH
- glykosidy chemie izolace a purifikace MeSH
- molekulární struktura MeSH
- nanotechnologie * MeSH
- stereoizomerie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- beta-cyklodextriny MeSH
- flavanony MeSH
- glykosidy MeSH
The synthesis and characterization of two thiophenol-modified fluorographene derivatives, namely methoxythiophenol-and dimethylaminothiophenol-modified fluorographenes, are reported, while their third-order nonlinear optical response were thoroughly investigated under both visible (532 nm) and infrared (1064 nm) with 35 ps and 4 ns laser pulses. The graphene derivatives were obtained by partial nucleophilic substitution/reduction of fluorographene by the corresponding organic thiophenols, and were fully characterized by techniques including infrared/Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force spectroscopy, and high-resolution transmission microscopy. This type of modification resulted in graphenic structures where the attached thiol groups, sp2 domains, and the residual fluorine groups act as donors, π bridges, and acceptors, respectively. Both derivatives exhibited large nonlinear optical response compared to fluorographene, and have potential applications in optical limiting as an alternative to fullerenes.
- Klíčová slova
- fluorographene, nonlinear optical properties, optical limiting, surface modification, thiophenol derivatives,
- Publikační typ
- časopisecké články MeSH
