Peter Mikuš has completed his PhD from Comenius University (Slovakia). He is Researcher, University Teacher, Associated Professor, and Director of the Toxicological and Antidoping Center at the Faculty of Pharmacy Comenius University in Bratislava (FPCU) as well as Head of the Department of Pharmaceutical Analysis and Nuclear Pharmacy FPCU. His one research team is focused on the development, validation and application of advanced hyphenated analytical methods, based on a combination of 2D-separation and spectral (UV-VIS, MS/MS) techniques, for pharmaceutical and biomedical research. He has published more than 60 papers in reputed CC journals.
A powerful tool for the analysis of unpretreated or diluted biological samples containing ultra-trace concentration levels of ionizable drugs and their ionizable metabolic products, based on the two-dimensional isotachophoresis–capillary zone electrophoresis (ITP-CZE) technique on-line hyphenated with the electrospray ionization–tandem mass spectrometry (ESI-MS/MS, here triple-quadrupole mass spectrometry, QqQ), was developed in our work. Analytical and application potentialities of this new approach were demonstrated on the highly reliable determination of pg-ng/mL levels of various cationic drugs (varenicline, pheniramine) and identification of their cationic metabolites (2-hydroxyvarenicline, N-desmethyl pheniramine) in directly injected (unpretreated) human urine samples taken after the administration of a usual dose of the varenicline- or pheniramine-containing commercial drugs (Champix®, TheraFlu®). The success of the proposed method is linked with the enhanced sample loadability of the used CE system, on-line electrophoresis sample pretreatment (preconcentration and sample clean-up) and separation, high compatibility of CZE and ESI electrolyte systems, and mass spectrometry detection sensitivity and selectivity. The proposed ITP-CZE-ESI-QqQ method was approved by its favorable performance parameters such as the limit of detection, limit of quantitation, linearity, linear range, precision (intra-day, inter-day), recovery/accuracy, selectivity and robustness. Practical outcome of this study could drive advanced monitoring of target drugs, their metabolites and related biomarkers in biological samples, carried out in clinical laboratories for diagnostic purpose as well as therapy optimization.
Ksenija Kumrić has completed her PhD at the Faculty of Physical Chemistry, University of Belgrade, Serbia. She is employed at the Laboratory of Physics, Vinča Institute of Nuclear Sciences, Belgrade, Serbia and working on the project: Physics and chemistry with ion beams\" financed by the Ministry of Education, Science and Technological Development of Republic Serbia. Her research work is focused in the field of Separation Chemistry, especially membrane based separation processes and adsorption; and its application in Radiochemistry, Analytical and Environmental Chemistry. rnrn
Long-lived radionuclide 90Sr is an ideal source of carrier-free 90Y (T1/2=64.1 h, Emax=2.3 MeV), which has suitable radionuclidic characteristics for the application in endoradiotherapy of malignant tumors. Separation of Y(III) from Sr(II) with 15% (v/v) di(2-ethylhexyl)phosphoric acid (DEHPA) in dodecane was performed using the hollow fiber supported liquid membrane (SLM) contactor operated in a recirculation mode. The influence of various experimental parameters (contact time, donor pH, DEHPA concentration, donor and acceptor flow rates) on the mass transfer rate of Y(III) and the separation effects in the applied system was investigated. The steady-state was established after about 5-6 h of operation. A yield of Y(III) in the acceptor phase increased as the flow rate of both aqueous phases increased and reached 72% at the acceptor flow rate of 1.9 cm3min-1 and the donor flow rate of 4.7 cm3min-1. However, a breakthrough of Sr(II) through the SLM also increased with increasing the acceptor flow rate, so that flow conditions must be optimized to find a balance between the requirement for a high yield of Y(III) in the acceptor phase and a low breakthrough of Sr(II) through SLM. Hollow fiber SLM contactor operated in a recirculation mode under optimized flow conditions could be used for the development of 90Sr-90Y generator system and milking of 90Y in the form suitable for direct complexation with various chelating agents and preparation of 90Y-radiopharmaceuticals.