The nicotinic acetylcholine receptor (nAChR) subtypes alpha3beta4-nAChR and alpha4beta2-nAChR have been immobilized and the resulting stationary phases used to determine binding affinities. The alpha3beta4-nAChR column was coupled to a C(18) column and a mixture of 18 compounds was sorted into ligands and non-ligands for the alpha3beta4-nAChR. The results demonstrate that the nAChR stationary phases can be used for on-line high-throughput screening (HTS).