Green microextraction approach focuses on air-assisted dispersive liquid–liquid with solidified floating organic drop for preconcentration and determination of toxic metals in water and wastewater samples

In this issue, Co(II), Pb(II), and Pd(II) were separated using an economical and green microextraction technique. The air agitation was used as a green co-factor with dispersive liquid–liquid microextraction solidified floating organic drop (AA-DLLME-SFO), which addresses the major drawbacks of the previous techniques. The procedure involved the use of folic acid, 1-undecanol and acetone as chelating agent, extraction solvent and disperser, respectively. Co(II), Pb(II), and Pd(II) detection limits were 0.042, 0.022, and 0.055 µg L⁻¹, respectively. The preconcentration factors were 100 for all ions. For all metal ions investigated, the linearity has a wide range (0.5–100 µg L⁻¹). The increased sensitivity depends on lower detection limits and higher preconcentration factors. Standard reference materials were used to ensure the accuracy of this approach. The selected procedure was used to measure trace quantities of heavy metals in river water and wastewater samples using flame atomic absorption spectrometry with great success. Finally, the greenness of the applied technique was assessed using two tools, the Green Analytical Procedure Index (GAPI) and Analytical Greenness Metric (AGREE). The GAPI graphic has eight green boxes, four yellow boxes, and three red boxes, and the AGREE index yields a total score of 0.78. The AA-DLLME-SFO approach is an environmentally friendly and sustainable procedure. Graphical abstract: [Figure not available: see fulltext.]