Quantitative determination of melphalan DNA adducts using HPLC - inductively coupled mass spectrometry

For the quantification of Melphalan DNA adducts, an analytical approach based on the detection of phosphorus using liquid chromatography combined with inductively-coupled-plasma mass spectrometry (ICP-MS) was developed. In reaction mixtures of native 2'-deoxynucleotides-5'-monophosphates and Melphalan, which were separated using reversed phase chromatography, phosphate adducts were found as the most abundant modifications. Besides the phosphate adducts, several base alkylated adducts were observed. In calf thymus DNA incubated with Melphalan and enzymatically digested using Nuclease P1, the phosphate adducts as well as monoalkylated dinucleotides were found. The most abundant single Melphalan adduct observed in DNA was a ring-opened adenosine monophosphate. Some dinucleotide adducts and the adenosine adduct were identified using electrospray ionization mass spectrometry (ESI-MS).