Flame atomic absorption spectrometric determination of Cd, Pb, and Cu in food samples after pre-concentration using 4-(2-thiazolylazo) resorcinol-modified activated carbon

This work aimed to develop a solid-phase extraction method using low-cost activated carbon produced from waste and modified with 4-(2-thiazolylazo) resorcinol for Cd(II), Pb(II), and Cu(II). The results showed that quantitative recovery of analytes was obtained at pH 6 with 3 M nitric acid as the eluent and a sample volume up to 1000 mL. The method was validated using certified reference material and addition-recovery tests. The limits of detection (LODs) for Pb(II), Cd(II), and Cu(II) were 2.03 μg L−1, 0.15 μg L−1, and 0.19 μg L−1, respectively. The procedure was applied for determination of analytes in food samples.