Bioanalytical Chemistry

The research interest of the group is focused on qualitative and quantitative determination of endogenous plant hormones (cytokinins, auxins, brassinosteroids, abscisic and salicylic acids) and selected phenolic compounds. Our methods are based on mass spectrometry (MS) coupled to high performance liquid chromatography (HPLC), or ultra pressure liquid chromatography (UPLC). The later, high throughput strategy enables us to separate and analyze more than 20 (cytokinin) metabolites in just 4 minutes. For quantitative analysis we are currently using single or triple-quadrupole MS, combining high sensitivity (< 1 fmol) and a linear response over as much as five orders orders of magnitude. Qualitative analysis is usually performed using hybrid Q-Tof MS technology, which allows identification of compounds of interest using MS/MS spectra recorded at as little as 100 fmols; exact mass determination, giving the elemental composition of the analyte, is also possible. Immunoaffinity chromatography using both polyclonal and monoclonal antibodies is employed as an integral part of our purification procedures, resulting in highly purified samples prior HPLC-MS analysis. This further enhances the detection limits of our analytical methods. Using in vivo deuterium incorporation coupled with HPLC-MS analysis allows us to quantify biosynthetic rates for different plant hormone metabolites . This enables us to confirm the endogenous origin of analyzed compounds, to construct and confirm metabolic pathways and to determine the sites of their biosynthesis.

Group Members
Ondřej Novák
Danuše Tarkowská
Petra Amakorová
Eva Hényková
Jiří Grúz
Jarmila Greplová