Separation and identification of phenolic compounds in canned artichoke by LC/DAD/ESI-MS using core–shell C18 column: A comparative study

Core–shell silica stationary phase was considered as a breakthrough in column technology in HPLC world. In this work, the chromatographic performance of core–shell column, made by fusing a 0.5 μm porous silica layer onto 1.7 μm nonporous silica cores, was compared with sub-2 μm fully porous particle materials for separation and identification of phenolic compounds in canned artichoke heads. The anti-oxidant caffeoylquinic acids of artichoke extract was taken as representative for calculating the plate heights in a wide flow rate range and analyzed on the basis of the van Deemter and Knox equations. Theoretical Poppe plots were constructed for each column to compare their kinetic performance. Both phases gave similar minimum plate heights when using non-reduced coordinates. Meanwhile, the flat C-term of core–shell column provided the possibilities for applying high flow rates without significant loss in efficiency. In addition, the peak capacities of both columns were measured, at constant chromatographic linear velocity and intrinsic gradient steepness, in order to generate comparable retention window for the least and the most retained compounds. Finally, the core–shell column was successfully applied for separation and identification of 10 phenolic compounds in canned artichoke extracts by liquid chromatography–diode array detection–tandem mass spectrometry, exhibiting great potential in the field of food analysis.

► The performance of core–shell column was compared with porous sub-2 μm column.
► The comparison was performed in both isocratic and gradient elution modes.
► The van Deemter, Knox, Poppe plots and back pressures of both columns were studied.
► The peak capacities of both columns were measured and compared.
► 10 phenolic compounds of canned artichoke head identified by core–shell-LC/DAD/MS.