IEC-Removing NaOH
 

Hi all. I use 0.5 M NaOH for cleaning anion and cation exchange resins after protein purification and I need a quick/efficient way of removing the NaOH before storage in 20% ethanol. H2O does not work quickly enough - can take more than 10 column volumes. I think I need a buffer at high concentration (1M) that can displace the OH- ions quickly, then I would follow with H2O (so salts won't precipitate when ethanol is used later for storage). I'm hoping to use maybe 1 column volume of high concentration buffer and 2-3 column volumes of H2O. Which buffer(s) would work well? I would prefer to use the same buffer for all cation and anion resins if possible for convenience. Any advice?