Zdrojový dokument:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 20/2014
ISSN:1211-5541
Abstrakt:
We studied the influence of mobile phase composition on the retention of phenolic
acids and flavonoid compounds on five different hydrosilated silica-based
stationary phases in buffered aqueous acetonitrile. Cogent UDC cholesterolTM,
Cogent bidentate C18TM and Cogent Phenyl hydrideTM columns show significant
dual reversed-phase/normal-phase retention behaviour, while Cogent Diamond
hydrideTM and Cogent Silica-CTM columns provide very low retention in the
reversed-phase mode. The effect of the aqueous acetate buffer concentration on
retention factors of phenolic acids and flavonoid compounds over the full mobile
phase composition range, including both aqueous normal-phase (ANP) and
reversed-phase (RP) mechanisms, can be described by a four-parameter equation
for dual-retention mechanism. At increasing temperature, the retention factors
and peak widths decrease in the aqueous normal-phase range. In agreement with
van’t Hoff model, linear ln k versus 1/T plots were observed, showing a single retention mechanism. From among the stationary phases tested, Cogent UDC
cholesterolTM column has high temperature stability (up to 100 °C) and provides
the most selective and efficient separations of flavones in the ANP mode and
Cogent Diamond hydrideTM is the most selective and effective for separation of
phenolic acids.