B. Handling
B. Handling
The experimental procedures given in table 6 should be applied for quantitatively transferring an ion exchange resin from one ionic status into another. An excess of reagents is applied to ensure completeness of the reactions. This is epecially necessary for ions with strong binding to the resin, e.g. for iodide.
Technical grade ion exchangers should be conditioned before use by a cycle of washing process as listed in table 6, e.g. with HCl and NaOH and intermediate washing with water and alcohol (the latter for leaching out monomers and other organic impurities). The conversion into the requested ion form can be done by column washing.
Analytical grade ion exchangers are ready for use – after washing with water or equilibrating with buffer. After use, they are reconditioned as listed in table 6.
For many simple laboratory applications, glass columns of 10 – 30 cm length and an internal diameter of about 1 cm are used. The column is filled at first with dist. water and the resin – in a slurry with water – is poured into it, settling to the bottom in even layers. Care must be taken to prevent air bubbles from being trapped in the resin bed. After rinsing with water or –depending on the application – after equilibration with buffer, the resin is ready for use.