Lewis acid and oxidant impurities are removed from inert fluids by contacting with a high capacity macroreticulate polymer comprising a macroreticulate polymer backbone having a plurality of pendant functional groups or mixtures of functional groups having the general formula: ##STR1## where Ar is an aromatic hydrocarbon radical containing from one to three rings; R.sub.1 and R.sub.2 are the same or different and are selected from the group consisting of hydrogen, alkyl hydrocarbon radicals, methylene-bridged benzophenone radicals, salts of methylene-bridged benzophenone, methylene-bridged fluorenone radicals and salts of methylene-bridged fluorenone; and M is selected from the group consisting of lithium, potassium, sodium, alkyl magnesium, and alkyl zinc.