Dispersive liquid-liquid microextraction assisted by modified lead(IV) nanoparticles for quantitative analysis of ofloxacin

A practical and simple modified lead(IV) nanoparticle-disepersive liquid-liquid microextraction(MPbNps-DLLME) has been successfully applied as electrostatic affinity probes to themicroextraction and preconcentration of ofloxacin prior to spectrofluorimetry analysis. Thistechnique is based on a ternary system of solvents, where appropriate amount of microextractioncontaining tetraalkylammonium bromide coated lead(IV) nanoparticles (PbNPs), and dispersersolvents are directly injected into an aqueous solution containing ofloxacin. A cloudy mixture isformed, and ofloxacin in the aqueous matrix is extracted into the fine droplets of microextractionsolvent containing PbNPs. The settled phase is collected and transferred into a micro-cell offluorimeter for the determination of ofloxacin at excitation/emission wavelengths of 335/375 nm.The obtained results demonstrated that electrostatic attraction forces caused by PbNPs were muchstronger than the hydrophobic attraction forces. Various factors influencing microextractionefficiency were studied and optimized. Under the optimum conditions, the method provided arelatively broad linear dynamic range of 0.1 to 150 ng mL−1, a detection limit of 0.02 ng mL−1 and arelative standard deviation of 2.1%. Finally, the method was successfully applied to ofloxacindetermination in actual pharmaceutical formulations and human urine sample.

Keywords:

Lead(IV) nanoparticles , Ofloxacin , Spectrofluorimetry , Dispersive liquid-liquid microextraction , Urine