RESUMO
In this study, a novel monolithic capillary column based on a NH2-MIL-53(Al) metal-organic framework (MOF) incorporated in poly (3-acrylamidophenylboronic acid/methacrylic acid-co-ethylene glycol dimethacrylate) (poly (AAPBA/MAA-co-EGDMA)) was prepared using an in situ polymerization method. The characteristics of the MOF-polymer monolithic column were investigated by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, Brunauer-Emmett-Teller analysis, and thermogravimetric analysis. The prepared MOF-polymer monolithic column showed good permeability, high extraction efficiency, chemical stability, and good reproducibility. The MOF-polymer monolithic column was used for in-tube solid-phase microextraction (SPME) to efficiently adsorb trace sulfonamides from food samples. A novel method combining MOF-polymer-monolithic-column-based SPME with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was successfully developed. The linear range was from 0.015 to 25.0 µg/L, with low limits of detection of 1.3-4.7 ng/L and relative standard deviations (RSDs) of < 6.1%. Eight trace sulfonamides in fish and chicken samples were determined, with recoveries of the eight analytes ranging from 85.7% to 113% and acceptable RSDs of < 7.3%. These results demonstrate that the novel MOF-polymer-monolithic-column-based SPME coupled with UHPLC-MS/MS is a highly sensitive, practical, and convenient method for monitoring trace sulfonamides in food samples previously extracted with an adequate solvent.
Assuntos
Análise de Alimentos , Polímeros/química , Microextração em Fase Sólida , Sulfonamidas/análise , Espectrometria de Massas em Tandem , Adsorção , Animais , Calibragem , Galinhas , Cromatografia Líquida de Alta Pressão , Peixes , Concentração de Íons de Hidrogênio , Estruturas Metalorgânicas , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios XRESUMO
OBJECTIVE: To study the phenolic constituents from Ampelopsis grossedentata. METHODS: Compounds were isolated using column chromatographic techniques (silica gel, polyamide gel, Sephadex LH-20) and semi-preparative HPLC. Structures were elucidated on the basis of spectral data (NMR and HR-MS). RESULTS: Eight compounds were isolated and identified as ampelopsin (I), 5, 7, 3',4',5'-pentahydroxyflavanone (II), galloyl-beta-D-glucopyranoside (III), gallic acid (IV), ethyl gallate (V), myricitrin (VI), (2R, 3S)-5,7,3',4',5'-pentahydroxyflavanonol (VII) and myricetin (VIII). CONCLUSION: Compounds II and VII are obtained from this genus for the first time.
Assuntos
Ampelopsis/química , Medicamentos de Ervas Chinesas/química , Fenóis/química , China , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Ácido Gálico/química , Ácido Gálico/isolamento & purificação , Fenóis/isolamento & purificação , Folhas de Planta/química , Caules de Planta/químicaRESUMO
OBJECTIVE: To establish a method for determing the content of two isomers containd in Garcinia hanburyi by HPLC. METHOD: Chromatographic column of SunFire (Waters) C8 (2.1 mm x 150 mm, 3.5 microm) was adopted, with acetonitrile-methanol-0.3% trifluoroacetic acid (36: 37:27) as the mobile phase. The detection wavelength was 360 nm,the flow rate was 0.3 mL x min(-1), and the column temperature was 28 degrees C. RESULT: The linear regression equation of r-gambogic acid was Y = 2.87 x 10(6) X - 2.24 x 10(5), r = 0.999 9. The linear regression equation of S-gambogic acid was Y = 3.31 x 10(6) X - 1.44 x 10(5), r = 0.999 9. The average recoveries were 100.0% and 100.9%, with RSD being 2.1% and 2.5% (n = 6), respectivley. The average contents of two gambogic acid in G. hanburyi were 30.06% and 21.45%, respectively. CONCLUSION: The method was so convenient and stable that it can be used for identification and content determination of two isomers containd in G. hanburyi.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Garcinia/química , Xantonas/análise , Isomerismo , Modelos LinearesRESUMO
OBJECTIVE: To determine the total content of astragaloside IV in Radix Astragali. METHODS: The measurement conditions were used as follows: Irregular C18 (4.6 mm x 250 mm, 5 microm) column; mobile phase: acetonitrile-water (32:68); flow rate: 1.0 ml/min; detector: ELSD 2000; the temperature of drift tube: 100 degrees C; gas flow: 2.7 L/min. RESULTS: Eight batches of Radix Astragali from different sources were determined. The stability, precision and reproducibility of the method were studied, RSD <3%. CONCLUSION: There is great difference between the content of astragaloside IV in Radix Astragali by different processing methods.