Concentration of mutagens from urine by absorption with the nonpolar resin XAD-2: cigarette smokers have mutagenic urine.

A method is described for concentrating mutagens/carcinogens from human urine about 200-fold for subsequent assay in the Salmonella/mammalian microsome mutagenicity test. The method is also applicable for other aqueous liquids and for other in vitro tests for mutagens/carcinogens. The urine (up to 500 ml) is put through a column with a 1.5-cm3 bed volume of XAD-2 (styrene-divinylbenzene polymer) and the adsorbed material is then eluted with a few milliliters of acetone. The acetone is taken to dryness and the residue is dissolved in dimethyl sulfoxide. This is the urine concentrate that is assayed for mutagenicity. Various mutagens/carcinogens have been added to human urine and the recoveries have been measured after adsorption on XAD-2, XAD-4, and Tenax GC (diphenyl-p-phenylene oxide polymer). We propose that this method be used in monitoring the urine of human populations and of experimental animals in toxicological studies. It is shown with this procedure that cigarette smokers have mutagenic urine while nonsmokers do not.