Dispersive liquid-liquid microextraction assisted bymodified Lanthanum nanoparticles for quantitative analysisof ofloxacin

A practical and simple modified Lanthanum nanoparticle-disepersive liquidliquidmicroextraction (MLaNps-DLLME) has been successfully applied aselectrostatic affinity probes to the microextraction and preconcentration ofofloxacin prior to spectrofluorimetry analysis. This technique is based on aternary system of solvents, where appropriate amount of microextractioncontaining tetraalkylammonium bromide coated Lanthanum nanoparticles(LaNps), and disperser solvents are directly injected into an aqueoussolution containing ofloxacin. A cloudy mixture is formed, and ofloxacin inthe aqueous matrix is extracted into the fine droplets of microextractionsolvent containing LaNps. The settled phase is collected and transferredinto a micro-cell of fluorimeter for the determination of ofloxacin atexcitation/emission wavelengths of 335/375 nm. The obtained resultsdemonstrated that electrostatic attraction forces caused by LaNps weremuch stronger than the hydrophobic attraction forces. Various factorsinfluencing microextraction efficiency were studied and optimized. Underthe optimum conditions, the method provided a relatively broad lineardynamic range of 0.1 to 150 ng mL−1, a detection limit of 0.02 ng mL−1 anda relative standard deviation of 2.1%. Finally, the method was successfullyapplied to ofloxacin determination in actual pharmaceutical formulationsand human urine sample.

Keywords:

Lanthanum nanoparticles , Ofloxacin , Spectrofluorimetry , Dispersive liquidliquidmicroextraction