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Off‐line comprehensive two‐dimensional hydrophilic interaction×reversed phase liquid chromatographic analysis of green tea phenolics
Author(s) -
Kalili Kathithileni M.,
de Villiers André
Publication year - 2010
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200900673
Subject(s) - flavonols , chemistry , chromatography , proanthocyanidin , high performance liquid chromatography , reversed phase chromatography , chromatography detector , green tea , composition (language) , flavonoid , organic chemistry , polyphenol , antioxidant , linguistics , food science , philosophy
The separation of green tea phenolic compounds by comprehensive 2‐D LC (LC×LC) has been studied. An off‐line LC×LC system was designed based on hydrophilic interaction chromatography in the first dimension and gradient RP‐LC using a C18 column in the second dimension, to separate compounds based on polarity and hydrophobicity, respectively. Green tea was found to contain a complex composition of low molecular weight phenolic compounds, identified by fluorescence, diode‐array and negative ESI‐MS detection systems. The LC×LC system was characterized by a very high practical peak capacity (>2100, in ∼22.5 h) due to the low degree of correlation ( r 2 <0.2) between the selected separation mechanisms. The proposed methodology demonstrated its suitability for the analysis of various groups of phenolic compounds including proanthocyanidins, phenolic acids, flavonols and flavonol derivatives, all of which cannot be separated in a single analysis by conventional 1‐D HPLC methods.