4. Conclusions
The enantioselective SPE-HPLC-FD method using Chirobiotic V
column demonstrated to be accurate and precise to quantify in a
single run the enantiomers of FLX and the enantiomers of its demethylated
metabolite NFLX in wastewaters. The optimized mobile
phase used a green choice with ethanol as organic solvent. The
selectivity and LOQ achieved by the fluorescence detector were
adequate for monitoring the degradation assays at environmental
level. This validated method was successful applied in the biodegradation
assays using real wastewater samples spiked with FLX.
Trace of FLX remained until 46 days of the assays, however nonenantioselective
degradation and no formation of enantiomers of
the metabolite NFLX were observed. This is in accordance with previous
publications which enforce that the degradation pattern and
the enantioselectivity depend very much on the microorganism
phylogenies.