A new sorbent of modified MWCNTs for column preconcentration of ultra trace amounts of zinc in biological and water samples

► Multi walled carbon nanotubes was used for preconcentration of Zn(II). ► The modification of MWCNTs is simple; it can be used several times. ► Under the optimum condition, zinc in aqueous samples was concentrated 250 fold. ► The procedure has low detection limit and high tolerance limit to interferences.