Sorting tags for chromatography allow mixtures of substrates to be carried through parallel chemical processes and then separated. The first sorting tags were fluorocarbons. An enabling characteristic of fluorous sorting tags is the predictable incremental increase in retention time with increasing fluorocarbon chain length. Here we describe a general approach to sorting tags and report our discovery of a second class of chromatographic tags. The new tags are oligomeric ethylene glycol (OEG) derivatives. (C) 2005 Elsevier Ltd. All rights reserved.