Mrs/Miss Scaria,

Tetracycline is a unsuitable analyte for analysis by UV-VIS spectroscopy, due to (i) the saturated molecular structure, excluding from the substitute benzene fragment; and (ii) the presence of a large number of same type of chromophores. Furthermore, (iii) there are a large number of tautomeric forms, which complicate further the experimental assignment of the UV-VIS bands of the analyte itself and its degradation products.

Of course, if there is used complementary experimental UV-VIS spectroscopy with theoretical quantum chemical analysis of the electronic structure and the electronic transitions of the analyte and its degradation products, then there would be obtained a reliable assignment of the experimental data.

The method of choice for such study, like yours is the mass spectrometry; however, within the framework of our (mine and my co-author's) innovative stochastic dynamic theory and model formulas.

Please, consider more detail on reference [1] and the corersponding reference section cited, therein.

[1] Steroids, 164 (2020) 108750

Stochastic dynamic mass spectrometric quantification of steroids in mixture — Part II; Bojidarka Ivanova, Michael Spiteller

Thank you Bojidarka B. Ivanova for the constructive suggestions.