Preparation of ferric oxide-aluminium oxide carbon nanofiber nanocomposites for ultrasound-assisted dispersive magnetic solid phase extraction of 17-beta estradiol in wastewater

In this work, Fe₃O₄-Al₂O₃@CNFs nanocomposite was synthesised and used as a nanosorbent in the ultrasound-assisted dispersive magnetic solid phase extraction (UA-DMSPE) of 17-beta estradiol (E2) in wastewater samples. The quantification of E2 was achieved using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). Various parameters affecting the efficiency of this sample preparation technique were optimised to achieve excellent sensitivity and high recoveries of E2. Response surface methodology was utilised for optimisation of these parameters. Using the optimised conditions, the linear dynamic range was achieved in the range of 0.1–1000 μg L⁻¹ and the correlation coefficient was found to be 0.9981. The preconcentration factor, enrichment factor, limit of detection (LOD) and limit of quantification (LOQ) were 67, 169, 0.025 μg L⁻¹ and 0.083 μg L⁻¹, respectively. The relative standard deviation (%RSD) for the intraday (n = 10) and interday (n = 5 working days) were 1.8% and 3.3%, respectively. The developed UA-DMSPE/HPLC-DAD method was applied for the preconcentration and determination of E2 in wastewater samples. The obtained results indicated that E2 was present in the wastewater samples.