An embodiment of the present invention is a method for isolating conducting polymer precursors by contacting a non-basic heterocyclic nitrogen containing hydrocarbon stream having a boiling point of from 232° C. (450° F.) to 566° C. (1050° F.) with an effective amount of a treating agent selected from the group consisting of alkylene and polyalkylene glycols and glycol ethers and mixtures thereof, having a molecular weight of less than 1000 and 1200, respectively, at conditions effective to maintain the reactants in a liquid phase to produce a first stream enriched in non-basic heterocyclic nitrogen containing hydrocarbon compounds and a second treated stream having a decreased non-basic heterocyclic nitrogen content. Optionally, an effective amount of a mineral acid may be added to the treating agent to enhance the process.