The NPs solution contains the sodium citrate as a stabilizer. These citrates are around NPs and contain COO -carboxylate functions which can disturb the XPS analysis of NPs grafted with dizonium salts contain COOH. In this regard, we removed the citrates from the NPs solution by the dialysis method using semi-permeable exchange cellulose membranes. The time required for optimal purification varies from 6 hours to 7 days. In our case the optimal purification time is three days (72 hours) considering the UV analysis. After this time the solution which was red and clear became a dark blue suspension with particles visible to the naked eye, that it shows the removal of citrates from the suspension and the aggregation of NPs. Due to the reversibility and disaggregation of these nanoparticles in solutions compatible with functional groups (hydrophilic and hydrophobic), this method can be a practical and effective method to store nanoparticles in solid state no grafted or grafted with various diazonium salts. For use in various hydrophilic and hydrophobic media, according to the ultimate goal of using these nanoparticles.