Quasifree electron attachment to carcinogens in liquid cyclohexane.
The quasifree electron attachment rate constant, kappa e, was measured in liquid cyclohexane at 20 degrees C for 76 chemicals that had been tested for bacterial mutagenicity in at least one of five earlier studies designed to determine the correlation between bacterial mutagenicity and animal carcinogenicity. A millionfold range of kappa e's was observed with the kappa e of 37 of 42 carcinogens being equal to or greater than the diffusion-controlled electron attachment rate constant, kappa d, of 2.9 x 10(12) M-1 s-1, whereas kappa e was less than kappa d for 30 of 34 noncarcinogens. These results yield a sensitivity of 88 percent for kappa e greater than or equal to kappa d indicating a chemical's carcinogenicity and a specificity also of 88% for kappa less than kappa d indicating a noncarcinogenic chemical. The observed quasifree electron attachment sensitivity and specificity compare favorably with previously observed Ames-test mutagenicity/carcinogenicity correlations which suggests that kappa e measurements also may be of value in a carcinogen-screening program.更多