Phase-system switching as an on-line sample pretreatment in the bioanalysis of mitomycin C using supercritical fluid...

One of the problems of the application of supercritical fluid chromatography (SFC) in bioanalysis is the fact that many sample pretreatment procedures deliver the solutes of interest in a polar solvent, which upon injection will dramatically disturb the phase system characteristics of the SFC system. The phase-system switching approach, recently introduced for liquid chromatography-mass spectrometry, can be used to avoid this problem. Plasma samples containing the thermolabile and pH-sensitive cytostatic drug Mitomycin C (MMC) were injected onto a short precolumn. After washing and drying of the precolumn the compound of interest was desorbed using a supercritical fluid and analyzed by SFC. Up to 1 ml of plasma containing 20 ng of MMC has been analyzed in this way.