Toner@cobalt ferrite nanocomposite based dispersive solid phase microextraction approach for the preconcentration of lead ions in bottled drinking water samples

In this method, a dispersive solid phase microextraction (DSPME) method was developed to determine the trace levels of lead (Pb 2+ ) ions with high accuracy in bottled drinking water samples using flame atomic absorption spectrometry (FAAS). Waste toner-based CoFe₂O₄ nanocomposite structures, which are expected to contribute to the literature as a newly synthesized sorbent material, were fabricated for the preconcentration of Pb²⁺ ions. The univariate optimization approach was implemented for all parameters that affect extraction efficiency, and under the optimal working conditions, the limit of detection (LOD) and limit of quantification (LOQ) were determined to be 5.0 and 16.5 µg L⁻¹ respectively. By comparing the slopes of the calibration plot equations for the FAAS and toner@CoFe₂O₄-based DSPME-FAAS methods, it was noted that the sensitivity was improved by 161.1 times. In recovery studies based on spiking with bottled drinking water samples, the recovery results ranged from 86.8% to 116.6% utilizing the matrix matching approach, thereby demonstrating the applicability of the method in drinking water samples. Greenness and practical applicability of the method were supported by BAGI and AGREEprep metrics with the scores of 65 and 0.44, respectively. On the other hand, the functionalization of toner particles obtained from waste cartridges and their first-time use as sorbent with a nanocomposite structure for the preconcentration of a metal ion demonstrated the originality and developability of the study.