Univerzita Pardubice Fakulta chemicko- technologická

Univerzita Pardubice

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Publikace detail

Separation of natural dyes using two-dimensional liquid chromatography

Autoři: Doležánová Pavla | Nováková Kateřina | Česla Petr

Rok: 2019

Druh publikace: ostatní - přednáška nebo poster

Strana od-do: nestránkováno

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
eng	Separation of natural dyes using two-dimensional liquid chromatography	This work is focused on optimization of separation of natural food dyes and natural antioxidants by liquid chromatography. We analysed porphyrin dyes that belong to the group of tetrapyrrole dyes, consisting of four pyrrole rings bonded by methine bridges. The antioxidants used were flavonoids and phenolic acids typically present in plant material. Both groups of dyes represent complex mixtures, which are not easy to analyse using conventional liquid chromatography. For separation of more complex samples, two-dimensional liquid chromatography (2D LC) can be applied, utilising two different chromatographic processes. The sample is separated on the first column, collected in the eluate fractions and further separated on the second column containing different stationary phase. The method can provide higher resolution with respect to the conventional LC, but the issues of dilution and compatibility of mobile phases should be avoided. In present work, the purity of available dye standards was verified using liquid chromatography coupled with mass spectrometry. To realize the two-dimensional liquid chromatography, the retention behaviour of the compounds in reversed-phase (RP) and hydrophilic interaction mode (HILIC) was studied utilizing orthogonal separation mechanisms suitable for 2D LC. We have studied retention using various stationary phases (RP: octadecyl silica gel and biphenyl, HILIC: silica gel) and mobile phase additives (ammonium acetate, ammonium formate, formic acid and acetic acid). We have evaluated effect of sample solvent on separation using different mixtures of acetonitrile and water. In 2D LC mode, we have tested different gradient profiles, loop sizes and switching times for separation of standards of porphyrin dyes, chlorophyllin sample and mixture of antioxidant standards.