Surfactant-enhanced spectrofluorimetric detection after magnetic nanoparticles-based micro-solid-phase extraction coupled with dispersive liquid–liquid micro-extraction for determination of ciprofloxacin in human plasma

Abstract

A sensitive and fast micro-solid-phase extraction (μ-SPE) coupled with dispersive liquid–liquid micro-extraction (DLLME) was reported before micelle enhanced spectrofluorimetric detection for determination of ciprofloxacin antibiotic in human plasma samples. The DLLME was performed using methanol as disperser and 1-octanol as extracting solvent. Oleic acid-modified Fe3O4 nanoparticles (as hydrophobic adsorbents) were applied in μ-SPE step to extract the analyte from DLLME procedure. The method uses the advantageous of high surface area and strong superparamagnetism of these nanoparticles to many avoid labourhood column/cartridge-passing processes of traditional SPE. The major parameters affecting signal enhancement and analyte recovery were evaluated and optimised. Under the optimal conditions, the calibration curve (with calibration equation of If = 2.5826 C + 10.273) was linear in the range 0.5–600 μg L−1 (R2 = 0.997) with low limit of detection of 0.21 µg L−1 and limit of quantification of 0.63 µg L−1. The intra-day and inter-day precisions (as relative standard deviation) were in the range of 1.01–1.67% and high recoveries in the range of 93.5–102.4% were obtained. The results demonstrated that the proposed method is easy, low cost, and accurate. In addition, it confirms that choosing extraction solvent was not restricted to the high-density solvents which can extent the versatility of DLLME.