The reaction between analyte ions and the complexing agent can be influenced by changes of pH value. For investigation the effect of pH on metal ion recoveries a set of similar experiments at fixed optimum value of all variable in the pH range of 2–10 has been carried out and respective results are depicted in Fig. 1. The highest uptake value was recorded at pH 6 using 2-HIYPMI as modified. This may be attributed to the presence of free lone pair of electrons on nitrogen and deprotonated oxygen atoms which made it suitable ligand for coordination with the metal ions.