The 3′-monophosphates of the major deoxyr ibonucleoside adducts of five representative polynuclear aromatic hydro carbons (PAH)-benzo[a]pyrene, benz[a]anthracene, chrysene, 5-methylchrysene and 6-methylchrysene-were prepared by reaction with DNA of the appropriate bay-region diol epoxides followed by enzymatic hydrolysis and HPLC purification. These standards were converted to 3′, [32p]-5′-bisphosphates as in the Randerath 32P-postlabeling assay. TLC and HPLC systems for their separation are described. HPLC conditions for separation of the corresponding 3′-and 5′monophosphates are also reported. These data will be useful for determining whether unknown DNA adducts detected by the 32P-postlabeling assay may have resulted from reactions of DNA with PAH diol epoxides.