Selective Removal of Silver Impurity from Oxaliplatin by Sorption on Functionalized Polymer

This report relates to synthesis of functionalized polymeric adsorbents for selective removal of silver ion in the presence of platinum(II) from crude oxaliplatin, thus providing an effective method for its purification with a desired impurity profile for silver. Two chelating ligands, thiourea and thiosemicarbazide, were grafted on styrene backbone cross-linked with 2% divinyl benzene (DVB) and tested by batch adsorption studies for the uptake of silver and platinum. The maximum sorption capacity values for both the adsorbents for Ag+ were 101.58 and 67.75 (mg/g), respectively, with an exceptionally high value of separation factor (alpha = 1155 and 231) over platinum. The experimental sorption data were fitted well with the Langmuir model. Desorption of silver from the polymer can be achieved by using 0.3 M Na2S solution for regeneration.