Abstract
In this study, we preconcentrated Cu, Zn, and Mn from Nile river and tap water at Cairo City (Egypt) by solid-phase extraction prior to flame AAS determination. Diacetylmonoxime functionalized silica gel (DMO-SG) was used as sorbent for preconcentration/separation of metal ions. Best sorption was achieved at sample pH 6 and flow rate of 2 mL min(-1). Desorption was affected by a 0.3 mol L-1 of hydrochloric acid solution. Sorption kinetic and isotherm were found to follow the pseudo-second-order and Freundlich isotherm models, respectively. The capacity was 422, 533, and 346 mu g g(-1) for Cu, Zn, and Mn, respectively. The limit of detection (3 sigma) was 0.10, 0.11, and 0.12 mu g L-1 and preconcentration factor was 100, 105, and 50, respectively. The recovery ranged between 92 and 102% and RSD % varied from 2.6 to 7.4%.