Assessment of norfloxacin degradation induced by plasma-produced ozone using surface-enhanced Raman spectroscopy

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Plasma Science

Background:

• Norfloxacin, a widely used antibiotic, can persist in the environment, necessitating effective degradation strategies.
• Understanding the degradation mechanisms of norfloxacin is crucial for developing efficient remediation technologies.
• Oxygen plasma produced ozone is a promising advanced oxidation process for pollutant degradation.

Purpose of the Study:

• To investigate the degradation pathways and mechanisms of norfloxacin using oxygen plasma produced ozone.
• To identify the main degradation products and elucidate the chemical transformations involved.
• To establish a quantitative surface-enhanced Raman spectroscopy (SERS) method for assessing the primary degradation pathway.

Main Methods:

• Surface-enhanced Raman spectroscopy (SERS) was utilized to analyze norfloxacin degradation products.
• Density functional theory (DFT) calculations were employed to support the mechanistic investigations.
• Oxygen plasma produced ozone was used as the degradation agent.

Main Results:

• The primary degradation pathway identified was the defluorination of norfloxacin.
• Spectroscopic analysis revealed the breakage of the carbon-fluorine bond.
• Fracture of the piperazinyl and quinolone moieties was also observed.
• The proposed SERS approach demonstrated quantitative assessment of the defluorination process.

Conclusions:

• Defluorination is the key mechanism in norfloxacin degradation by oxygen plasma ozone.
• SERS, in conjunction with DFT, provides a powerful tool for elucidating antibiotic degradation pathways.
• The developed SERS method offers a reliable way to monitor and quantify norfloxacin defluorination.