Analysis of urinary nucleosides. IV. Identification of urinary purine nucleosides by liquid chromatography/electrospray mass spectrometry.

Modified urinary nucleosides are potentially invaluable in cancer diagnosis. High-performance liquid chromatography (HPLC) was combined with full scan mass spectrometry (MS), tandem mass spectrometry and MSn analysis in order to identify purine nucleosides purified from urine. UV peaks evident in the chromatogram were examined by the various mass spectrometric techniques and adenosine, 1-methyladenosine, xanthosine, N1-methylguanosine, N2-methylguanosine, N2,N2-dimethylguanosine, N2,N2,N7-trimethylguanosine, inosine, and 1-methylinosine were each identified in the urine samples from cancer patients. The benefits of the use of LC/MS compared with HPLC alone are discussed.