Currently, solid-phase extraction by means of disposable columns has become a widely accepted technique for sample pretreatment in toxicology. In this method, however, the sample capacity is usually limited to a few milliliters. In this test of the extraction disks, human urine was selected as the matrix, and dexetimide and mepyramine were initially used as test drugs because they are available in tritiated form. Additional drugs investigated included codeine, hexobarbital, imipramine, methamphetamine, and nitrazepam. In these investigations, the sample capacity for untreated urine was at least 25 ml, and analyte quantities up to 250 mgs could be retained by these filters. Washing with water/methanol mixtures was effective in removing substantial amounts of endogenous interferences, and methanol proved to be an acceptable eluent. Thus, these disks apparently have the potential for toxicological analysis, in that sample concentration and cleanup can be achieved simultaneously. 3 figures, 1 table, and 7 references