Separation and preconcentration in a batch mode of Cd(II), Cr(III, VI), Cu(II), Mn(II, VII) and Pb(II) by solid-phase extraction by using of silica modified with N-propylsalicylaldimine. - Abou-El-Sherbini KS; Kenawy IM; Hamed MA; Issa RM; Elmorsi R (Talanta, 2002)