| 585 / | HD | CHEMISTRY OF HYDROCARBON COMPOUNDS |
| 800 | DF | PURIFICATION, SEPARATION, OR RECOVERY {7} |
| 833 | DF | .~ By addition of extraneous agent, e.g., solvent, etc. {15} |
| 864 | ![]() | .~.~ Organic agent {3} |
| 865 | DF | .~.~.~> Heterocyclic or polymeric |
| 866 | DF | .~.~.~> Acid, anhydride, ester or ether |
| 867 | DF | .~.~.~> Hydrocarbon |