Evaluation of the influence of various solvents for column storage in supercritical fluid chromatography

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Kateřina Lidvinová Supervisor: Assoc. Prof. PharmDr. Lucie Nováková, Ph.D. Title of Diploma Thesis: Evaluation of the influence of various solvents on column storage for supercritical fluid chromatography The diploma thesis deals with the evaluation of the influence of various solvents on column storage for supercritical fluid chromatography. It is focused especially on column aging which is manifested as reduced retention time and the change in selectivity of a stationary phase when stored for a certain period of time. The experiments were performed using the ACQUITY UPC2 SFC system with the PDA detector. The detection took place at wavelength of 225 nm for the mixture of neutral compounds and at wavelength of 230 nm for the mixture of ionisable compounds. The ACQUITY UPC2 BEH 1.7 µm and the ACQUITY UPC2 BEH 2-EP 1.7 µm columns with dimensions of 3.0 x 100 mm (Waters, USA) were used as stationary phases. After the separation, these columns were always flushed with different solvents and stored, namely in CO2, isopropanol, acetonitrile and hexane in which they were stored until the next use. CO2 with methanol as an organic modifier was used as a mobile phase for the mixture of..