Adsorption of chromium(III), mercury(II) and lead(II) ions onto 4-aminoantipyrine immobilized bentonite

▶ A new method was established for the preconcentration of Cr(III), Hg(II) and Pb(II). ▶ Cr(III), Hg(II) and Pb(II) binding only need 2 min. ▶ High adsorption capacity for Cr(III), Hg(II) and Pb(II). ▶ The precision and accuracy of the method are satisfactory.