Prisilna razgradnja torasemida i analiza razgradnih produkata 2D-LC-MS tehnikom

Autor: Mikulčić, Valentina
Přispěvatelé: Nigović, Biljana
Jazyk: chorvatština
Rok vydání: 2017
Předmět:
Popis: Dvodimenzionalna tekućinska kromatografija izravno povezanu s masenom spektrometrijom korištena je u analizi razgradnih produkata torasemida nastalih prisilnom razgradnjom. Uzorci torasemida bili su razgrađivani pri različitim uvjetima: 3 sata na 60⁰C, 24 sata na 105⁰C, u 1M HCl, u 1M NaOH i u 30% H2O2. Uzorci su analizirani jednodimenzionalnom tekućinskom kromatografijom, kako bi se provjerilo da je došlo do razgradnje i da ona nije pretjerana. Zatim su analizirani na dvodimenzionalnoj tekućinskoj kromatografiji izravno povezanoj na masenu spektrometriju. Dobiveni su kromatogrami nakon svake dimenzije, kao i maseni spektri razgradnih produkata. Nakon izlaska uzorka iz prve dimenzije, pomoću dobivenih kromatograma određena su vremena kada će se skupljati alikvoti za analizu u drugoj dimenziji. Analiza druge dimenzije pokazala je čistoću pikova nakon izlaska iz prve dimeznije, i njihovu dovoljnu odijeljenost. Slijedila je analiza na masenom spektrometru. Razgradni produkti ionizirani su pozitivnim ionizacijskim načinom i ioni razdvajani prema omjeru mase i naboja. Najzastupljeniji ioni ponovno su fragmentirani i dobiveni su njihovi MS/MS spektri. Uspoređivani su maseni spektri razgradnih produkata s pripadajućim MS/MS spektrima, a strukture razgradnih produkata crtane su u programu Chemdraw. Razgradnja torasemida najjača je u oksidirajućim uvjetima. Kiselom i bazičnom hidrolizom nastaje razgradni produkt mase 264,08. Njegova prisutnost utvrđena je u svim. To je najznačajniji razgradni produkt, a nalazi se među specificiranim onečišćenjima torasemida u Europskoj farmakopeji. Pomoću nacrtanih struktura pretpostavljeni su putevi razgradnje torasemida u različitim stresnim uvjetima. Two-dimensional liquid chromatography directly connected with mass spectrometry was used in the analysis of the degradation products of torasemide produced by forced degradation. Torasemide samples were degraded under different conditions: 3 hours at 60⁰C, 24 hours at 105⁰C, with 1M HCl, 1M NaOH and 30% H2O2. Samples were analyzed by one-dimensional liquid chromatography, to verify that the decomposition occurred and that it was not exaggerated. They were then analysed by two-dimensional liquid chromatography directly connected with mass spectrometry. The chromatograms obtained after each dimension, as well as the mass spectra of the degradation products, were obtained. After samples were eluated from the first dimension, it was determined, by using obtained chromatograms, when the aliquots for analysis in the second dimension will be collected. The second dimension analysis showed the purity of the peaks after the first dimensional eluation and their sufficient separation. Then the mass spectrometry analysis followed. The degradation products were ionized by positive ionization mode and the ions were separated by the mass and charge ratio. The most common ions were again fragmented and their MS/MS spectra were obtained. Mass spectra of degradation products were compared with corresponding MS/MS spectra, and the structures of degradation products were drawn in the Chemdraw program. Torasemide degradation was the thorough in oxidizing conditions. By acid and basic hydrolysis, the degradation product of mass 264.08 is formed. Its presence was confirmed in all samples. That is the most significant degradation product, and is among the specified impurities of torasemide in the European Pharmacopoeia. By means of the drawn structures, pathways of degradation of torasemide were assumed under different stress conditions.
Databáze: OpenAIRE
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