Fluorescence spectra presenting kinetic photodegradation of ciprofloxacin and levofloxacin

First derivative synchronous fluorescence spectroscopy (FDSFS) was applied
to detect and quantify ciprofloxacin (CIP) and levofloxacin (LEV)
simultaneously with their photodegradation products, where the photolytic
pathway for each analyte was found to be pH dependant. Under the guidance
of early published articles, the structure of the produced photolytic
products could be concluded, and further related to their resultant
fluorescence spectra. The proposed method was subjected to a full
validation procedure which enables its application in investigating the
photodegradation kinetics for both drugs. The obtained kinetic parameters
were in accordance with previous reports and could be linked to predict
the antibacterial activity of the resultant photodegradation products.
These facts prove the suitability of the suggested FDSFS to serve as a
stability-indicating assay method and to trace the photofate of CIP and
LEV in the ecosystem as potential contaminants. Furthermore, the greenness
of the suggested analytical methodology was evaluated via the ˝ Green
Analytical Procedure Index˝ (GAPI), which classifies it as an eco-friendly
assay. Eventually, no extraction, treatment, or preparation steps were
needed during all analysis steps, which renders the proposed assay an
appealing tool in environmental analysis.