RESULTS AND DISCUSSION
Effect of pH on Metal Ion Preconcentration.The effect of
pH on the retention of metal ions on the HAPTSC functionalized
Amberlite XAD-2- resin column was carried out over a wide
range of pH values (2.0-9.0) by applying the proposed SPEICPAES analyses procedure. The variation in sorption of metal
ions on the sorbent with pH is shown inFigure 1. These results
revealed that at pH 5.0 the quantitative sorption of three metals
was achieved. Hence, this pH was selected as the optimum pH
for SPE of metal ions.