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Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Taťána Gazárková Supervisor: prof. PharmDr. Lucie Nováková, Ph.D. Title of Diploma Thesis: Analysis of steroids from the group of androgens and glucocorticoids using UHPSFC-MS/MS The goal of this study was to develop and optimize an analytical method for the separation of 37 steroids mixture by the ultra-high performance supercritical fluid chromatography hyphenated to mass spectrometry (UHPSFC-MS/MS). Analysis was carried out using Waters Acquity UPC2 system coupled to Xevo TQ-XS mass spectrometer. In the first step it was necessary to consistently characterize the precursor ions of each analyte. Then, the Product ion scan was carried out and proper SRM transitions were chosen. Steroids are isomeric and isobaric substances that often provide the same precursor ions ([M+H]+ , [M+H-H2O]+ , eventually [M+H-2H2O]+ ), or similar fragmentation spectra. This is complicated by the fact that most intense ion of the spectrum is not always [M+H]+ , but also [M+H-H2O]+ ion which is simultanously isobaric m/z for a completely differnt compoud. After careful selection of SRM transitions, the conditions of the ion source were optimized for both positive and negative modes. In the next step, the screening of 18... |
