(191a) Adsorption of Fluoroquinolones at Gas-Liquid Interface By Foam Fractionation

Adsorption of fluoroquinolones at gas-liquid
interface by foam fractionation

Rajesh
Ghosh^1*, Haritha Hareendran², Subramanium
Pushpavanam^1*

¹Department
of Chemical Engineering,Indian Institute of Technology, Madras,
Chennai, 600036, India

²Department
of Chemical Engineering, Alagappa College of
Technology, Anna University, Chennai, 600025, India

*Contact:
ghoshrajesh1226@gmail.com, spush@iitm.ac.in

In this work we investigate the adsorption of
fluoroquinolone antibiotics at gas-liquid interface using ionic surfactants
such as sodium dodecyl sulfate (SDS) and cetrimonium
bromide (CTAB) using a foam fractionation technique. Ciprofloxacin (CF) is
chosen as a model fluoroquinolone. We investigate the effect of surfactant head
groups on the adsorption performance of the drug. CF being a zwitterionic
compound showed affinity towards both cationic and anionic surfactants.
Further, we probe the binding mechanism of the drug and surfactant using
infrared spectroscopy and nuclear magnetic resonance. The effect of the drug on
the foamability and production of bubbles (foam) is investigated using surface
tension analysis. It was found that the presence of CF in the solution mixture
increased the surface tension of the solution thus showing a trivial decline in
the foamability. This was also corroborated in the adsorption experiments. The
separation of the drug from the bulk mixture was most influenced by the pH of the
feed solution. A separation efficiency of more than 96% was obtained along with
an enrichment factor of 9.3. Overall, SDS showed a better separation efficiency
compared to the cationic surfactant indicating that the binding of the anionic
surfactant to the various protonated sites of the drug was a more dominant
factor for separation and adsorption to the gas-liquid interface.

Keywords: foam fractionation, fluoroquinolones, ionic
surfactants