Urine from cigarette smokers was prepared for mutagenicity testing by extracting mutagens with solid-phase extraction columns. Commercially available prepacked bonded silicas (octadecyl, cyclohexyl, cyanopropyl) were compared for their ability to concentrate the urinary mutagens. Recovered urinary metabolites were evaluated for mutagenic activity by using a microreversion assay with Salmonella typhimurium. Dose-response data indicated that while mutagens were recovered by all three adsorbents, samples prepared by using the bonded cyanopropyl columns yielded the most bioactivity and/or the least amount of test organism toxicity. Varying pH of the urine was found to influence only the basified samples in terms of mutagenic recovery with the cyanopropyl base. Combinations of different adsorbents were not found to offer significant advantages over use of a singular extraction adsorbent.