title: Analysis of polyphenols and methylxantines in tea samples by means of nano-liquid chromatography utilizing capillary columns packed with core-shell particles.
abstract: In this study, a rapid separation of eleven polyphenols and three methylxanthines was obtained by means of nano-liquid chromatography (nano-LC), employing a 100 μm I.D. capillary column packed with C18 core-shell particles (2.7 μm) for 10 cm. All compounds were baseline resolved with a step gradient elution in less than 15 min. The developed analytical method was validated and the resulting RSD% for intra-day and inter-day repeatability, related to retention time, retention factor and peak area, were below 5.1 and 5.7%. LOD and LOQ values corresponded to 0.300 and 0.625 μg/mL, while linearity range assessed gave R² no lower than 0.990. Then, the method was used to determine studied compounds in tea extracts. Further, the nano-LC system was coupled with a mass spectrometer to confirm the components present in real samples. Finally the results were compared with those obtained using a capillary column (100 μm I.D. × 10 cm) packed with C18 sub-2 μm particles, applying the same nano-LC experimental conditions.
authors.affiliation: Università Campus-Biomedico, Centro Integrato di Ricerca, Via Alvaro del Portillo 21, 00128 Roma, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Fanali
authors.forename: Anna
authors.initials: A
authors.lastname: Rocco
authors.forename: Zeineb
authors.initials: Z
authors.lastname: Aturki
authors.forename: Luigi
authors.initials: L
authors.lastname: Mondello
authors.forename: Salvatore
authors.initials: S
authors.lastname: Fanali
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives* / Q000032:analysis; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods*; D003373:Coumaric Acids / Q000032:analysis*; D013058:Mass Spectrometry; D036103:Nanotechnology / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013662:Tea / Q000737:chemistry*; D014970:Xanthines / Q000032:analysis*
chemical_list: D003373:Coumaric Acids; D013662:Tea; D014970:Xanthines; D002392:Catechin