Determination of benzo[a]pyrene-DNA adducts by solid-matrix phosphorescence

It has been demonstrated for the first time that linear relationships can be obtained between the solid-matrix phosphorescence (SMP) and the percent modification of benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE)-DNA adducts. The samples of DNA were modified with BPDE at levels of 5.0 x 10(-3), 1.0 x 10(-3), 5.0 x 10(-4), 1.0 x 10(-4), 5.0 x 10(-5), and 1.0 x 10(-5%). In addition, the changes in the SMP intensities of a given percentage of DNA adduct were investigated as a function of sample size, and linear relationships were also acquired. With the different percentages of modified DNA, very good reproducibility of the SMP signals was obtained. Data were acquired with both Whatman 1PS paper and 30% TlNO3/sodium acetate as solid matrixes. The limit of detection for the BPDE-DNA adducts was 2 adducts in 10(7) bases for both Whatman 1PS paper and 30% TlNO3/sodium acetate. In addition, it was shown that it would be important to develop a standard procedure for the preparation of the BPDE-DNA samples if different batches of DNA were used in the preparation procedure.