Comprehensive two-dimensional liquid chromatographic analysis of anthocyanins

Comprehensive two‐dimensional liquid chromatography for polyphenol analysis in foodstuffs

“…For polyphenol analysis, monolithic columns were first used in Mondello's group, due to their short regeneration characteristics and high permeability, thus allowing operation at high flow rates without substantial loss in resolution . Another way to speed up the 2 D analysis is to use conventional columns packed with stationary phases of reduced particle size such as partially or superficially porous stationary phases (Mondello, Dugo, Jandera, and Cifuentes’ groups) , or sub‐3 or sub‐2 μm particle packed columns (Hyötyläinen, de Villiers, and Jandera’s groups) ]. When using UHPLC conditions, the employment of hardware capable of withstanding high pressures (over 440 bar) is a must.…”

“…RP‐LC × RP‐LC and HILIC × RP‐LC (with the exception of the RP‐LC × HILIC in ref. ) have been developed and successfully applied to the analysis of polyphenolic compounds in real‐world food samples . Only one application dealt with the use of SEC and RP‐LC for analysis of Camellia sinensis green and black teas .…”

“…The first LC × LC system was introduced by Erni and Frei for the analysis of a complex plant extract with a SEC column as the 1 D and an RP column as the 2 D, connecting the two columns with a two‐position eight‐port switching valve . Since then, a broad range of papers on LC × LC have been published, covering applications and theoretical considerations; some of them are specifically devoted to polyphenol analysis and roughly 87% come from five different research groups very active in the field . Additionally, some reviews covering both theoretical and practical aspects for such bioactive molecules have been reported .…”

Theory and Practice of UHPLC and UHPLC–MS

“…In this regard, remarkable efforts have been made to extend the pressure capability of the pumping systems to 1300 bar. In addition, compared to old generation HPLC instruments, the contribution of the system to band broadening was dramatically reduced by using short and narrow connecting tubes, low injected volumes, small UV-cell volumes, and fast acquisition rates Jandera, 2012, 2016;Krol-Kogus et al, 2014;de Villiers, 2009, 2010;Beelders et al, 2015;Kalili et al, 2013;Montero et al, 2014;Willemse et al, 2014Scoparo et al, 2012).…”

“…A coreeshell column represents another possibility that can be used with conventional liquid chromatographic instrumentation . Online connection of a capillary HILIC column in the first dimension and an ultra-high performance RP-LC in the second dimension, coupled with MS, was used for highresolution separation and detailed characterization of anthocyanins and related pigments in berries and aged red wine (Willemse et al, 2014. Because of lower flow resistance, monolithic columns can be used in the second dimension at higher flow rates in comparison to particle-packed columns operated at the same operating pressure.…”