Abstract Thymidine 2′-deoxyadenosine were reacted with phenyl glycidyl ether in order to study the formation of the corresponding 2′-deoxynucleoside adducts. Separation methods were elaborated using either reversed-phase high-performance liquid chromatography with photodiode-array detection, or centrifugal circular thin-layer chromatography. The adducts were isolated on a preparative scale and were fully characterized by UV spectroscopy, desorption chemical ionization and fast atom bombardment mass spectrometry and 270- and 360-MHz 1H NMR spectrometry. For thymidine the main adduct was characterized as N-3-(2-hydroxy-3-phenoxypropyl)thymidine. With 2′-deoxyadenosine, predominantly N-l-(2-hydroxy-3-phenoxypropyl)-2′-deoxyadenosine was formed. With longer reaction times, the formation of a minor amount of dialkylated 2′-deoxyadenosine was observed. These nucleoside adducts will be used as marker compounds for studies of DNA adduct formation.