Simultaneous extraction and determination of Norfloxacin and Lomefloxacin based on magnetic dual-template molecularly imprinted polymer in water samples under multivariate optimization

Abstract

In the current investigation, we developed a pretreatment strategy for samples comprising Norfloxacin (NOR) and Lomefloxacin (LOM) using the molecularly imprinting technique. NOR and LOM were extracted from water samples using a magnetic dual-template molecularly imprinted polymer (Fe₃O₄@NH₂@MIP), which was synthesized, and studied by SEM and TEM. A central composite design optimized the main experimental variables, such as pH, Fe₃O₄@NH₂@MIP, ionic strength, contact time, and eluent solvent. The study determined that a pH of 4, 15 mg of Fe₃O₄@NH₂@MIP, 2 % ionic strength, 4 min of contact time, and 165 μL of eluent solvent were the optimal values of extraction parameters. With determination coefficients (R²) over 0.99, the calibration curves showed good linearity within the range of 2–500 ng mL⁻¹ under optimal circumstances. The results showed that the limits of detection (LODs) for LOM and NOR were 0.5 and 0.4 ng mL⁻¹, respectively. Additionally, 1.33 and 1.67 ng mL⁻¹ were obtained as the limits of quantification (LOQs) for NOR and LOM, respectively. Additionally, it was discovered that the enrichment factors for NOR and LOM were 69.25 and 66.83, respectively. Fe₃O₄@NH₂@MIP has a high adsorption capability (41.36 and 38.95 mg g⁻¹ for NOR and LOM, respectively) and positive imprinting effects (4.35 and 4.30 for NOR and LOM, respectively), according to the findings of the adsorption and enrichment investigation. Furthermore, the recoveries (89.4 % - 94.3 %) for the spiked samples were satisfactory, with relative standard deviations ≤4.75.