Application of pipette-tip solid-phase extraction technique for fast determination of levofloxacin from wastewater sample using cobalt metal-organic framework

In this research, a miniaturized solid-phase extraction method based on pipette tip solid-phase extraction (PT-SPE) was employed for the determination of levofloxacin. Cobalt metal-organic framework (CoMOF) was used as an adsorbent. Levofloxacin was determined using high-performance liquid chromatography and UV detection (HPLC-UV).  Important parameters that influence the extraction efficiency (i.e. pH, amount of adsorbent, extraction time, volumes of sample, and eluting solvent) were tested and optimized. Results indicated that the proposed method was validated over the range of 0.70 - 150.0 µg L-1. The relative standard deviation (RSD%) was below 2.75% for the levofloxacin. The limit of detection (LOD) of this method is 0.041 µg L-1. The preconcentration factor (PF) was obtained at 200 and the analysis time was around 10 min that confirming the reliability and accuracy of this method for extraction of levofloxacin. The PT-SPE procedure based on CoMOF adsorbent was efficiently extracted for levofloxacin more than 95%. In a static system, the adsorption capacity of CoMOF adsorbent for levofloxacin was obtained at 156.7 mg g-1 (n=10). The validation of results was successfully obtained for levofloxacin values based on the spiking real samples before determination by the HPLC technique.