“…Commonly applied off-line and on-line sample purification protocols for nucleic acids prior to mass spectrometric analysis include multiple ethanol precipitation [19], membrane filtration [20], solid-phase extraction [21], microdialysis [14], affinity purification [22,23], cation-exchange [24], ligand-exchange [13], magnetic particles [25], size exclusion chromatography [26], and high-performance liquid chromatography (HPLC) [27,28]. Ion-pair reversed-phase high-performance liquid chromatography hyphenated to electrospray ionization mass spectrometry (ICEMS) has been demonstrated to be a rapid and highly effective analytical tool for the characterization of PCR amplified sequences [15, 29 -31].…”