Photodegradation of Azathioprine in the Presence of Sodium Thiosulfate
| Autor: | N’ghaya Toulbe, Ion Smaranda, Catalin Negrila, Cristina Bartha, Corina M. Manta, Mihaela Baibarac |
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| Rok vydání: | 2022 |
| Předmět: |
Photolysis
Organic Chemistry Thiosulfates azathioprine IR spectroscopy photodegradation Raman scattering UV-VIS spectroscopy photoluminescence General Medicine Spectrum Analysis Raman Catalysis Computer Science Applications Inorganic Chemistry Azathioprine Spectroscopy Fourier Transform Infrared Physical and Theoretical Chemistry Molecular Biology Spectroscopy |
| Zdroj: | International Journal of Molecular Sciences; Volume 23; Issue 7; Pages: 3975 |
| ISSN: | 1422-0067 |
| Popis: | The effect of sodium thiosulfate (ST) on the photodegradation of azathioprine (AZA) was analyzed by UV-VIS spectroscopy, photoluminescence (PL), FTIR spectroscopy, Raman scattering, X-ray photoelectron (XPS) spectroscopy, thermogravimetry (TG) and mass spectrometry (MS). The PL studies highlighted that as the ST concentration increased from 25 wt.% to 75 wt.% in the AZA:ST mixture, the emission band of AZA gradual downshifted to 553, 542 and 530 nm. The photodegradation process of AZA:ST induced: (i) the emergence of a new band in the 320–400 nm range in the UV-VIS spectra of AZA and (ii) a change in the intensity ratio of the photoluminescence excitation (PLE) bands in the 280–335 and 335–430 nm spectral ranges. These changes suggest the emergence of new compounds during the photo-oxidation reaction of AZA with ST. The invoked photodegradation compounds were confirmed by studies of the Raman scattering, the FTIR spectroscopy and XPS spectroscopy through: (i) the downshift of the IR band of AZA from 1336 cm−1 to 1331 cm−1, attributed to N-C-N deformation in the purine ring; (ii) the change in the intensity ratio of the Raman lines peaking at 1305 cm−1 and 1330 cm−1 from 3.45 to 4.57, as the weight of ST in the AZA:ST mixture mass increased; and (iii) the emergence of a new band in the XPS O1s spectrum peaking at 531 eV, which was associated with the C=O bond. Through correlated studies of TG-MS, the main key fragments of ST-reacted AZA are reported. |
| Databáze: | OpenAIRE |
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