Univerzita Pardubice Fakulta chemicko- technologická

Univerzita Pardubice

Zaměstnanci
|
Studenti
English

Publikace detail

COMBINED HILIC-RP HPLC IN THE ANALYSIS OF POLAR COMPOUNDS IN FOOD AND BEVERAGES

Autoři: Jandera Pavel | Hájek Tomáš | Staňková Magda

Rok: 2017

Druh publikace: ostatní - přednáška nebo poster

Strana od-do: nestránkováno

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
eng	COMBINED HILIC-RP HPLC IN THE ANALYSIS OF POLAR COMPOUNDS IN FOOD AND BEVERAGES	In food analysis we often encounter moderately or strongly polar compounds, which are often insufficiently retained under conventional HPLC conditions using bonded alkylsiloxane stationary phases. The number of resolved compounds (the peak capacity) is usually significantly increased in two-dimensional HPLC. There, the analysis of a fraction collected from the first dimension is performed either off-line or on-line in the second dimension within the short time available for the collection of the next fraction. Best results are accomplished using columns with widely different retention mechanisms. To this aim, it is advantageous to combine conventional reversed-phase chromatography on bonded C18 columns with HILIC chromatography on polar columns in aqueous-organic mobile phases. HILIC conditions provide improved separation selectivity for separation of polar analytes. Short core-shell or silica-based monolithic columns in the second dimension can be combined with a longer microbore or capillary column in the first dimension. We developed an efficient organic polymer zwitterionic column, which can be used either in reversed-phase or in normal-phase (HILIC) mode for efficient separations of phenolic acids, polyphenolic compounds, flavonoids and related compounds. The selection of suitable uni-dimensional and two-dimensional separation conditions is of primary concern. As the new monolithic zwitterionic polymethacrylate column shows dual retention mechanism in mobile phases with low and high concentrations of acetonitrile, alternating RPxHILIC and RPxRP separations with increasing and decreasing acetonitrile gradients run serially in the first dimension can be performed with the same column combinations. The approach is illustrated by examples of separations of samples containing phenolic, polyphenolic and flavonoid compounds occurring in beverages and plant extracts.	HILIC-RP; HILIC; HPLC; POLAR COMPOUNDS; FOOD; BEVERAGES