Development of a purification procedure for the isolation of nucleosides from urine prior to mass spectrometric analysis

A chromatographic separation of nucleosides from urine has been developed i n order to facilitate their mass spectrometric analysis for clinical diagno sis. A number of chromatographic resins were studied in order to develop an effective and efficient purification procedure. The optimized sequential p rotocol comprises a centrifugation, acidification and neutralization step, followed by application of an affinity chromatographic column and finally f urther separation on an acidic cation exchange column and a basic anion exc hanger. This scheme shows effective clean-up of a standard radiolabelled nu cleoside with a recovery of 92.5%, and recovery of nucleosides added to uri ne samples before extraction showed recoveries of 72 - 82%.