Nuove tecniche di separazione in fase liquida (micro-HPLC ed Elettroforesi Capillare) accoppiate alla spettrometria di massa: applicazioni tossicologiche e biomediche

In the last decade, analytical techniques such as capillary electrophoresis (CE) and micro-HPLC have grown in interest, particularly in the areas where the analyte is present in traces in the sample, such as forensic toxicological analysis, food analysis, combinatorial chemistry and drug discovery. In particular, in the forensic field for many years gas chromatography has been the technique of choice, specifically for the robustness and high analytical sensitivity. This technique is particularly suitable for the rapid analysis of mixtures of volatile substances, but nevertheless is not suitable for highly polar, non volatile and thermally unstable substances, as many of the target drugs of forensic interest are. In most instances, these drawbacks can be overcome by introducing a derivatisation step, this however creates a new source of variability and complexity. High performance liquid chromatography (HPLC) was immediately utilized in all analytical areas, principally because it allows the use of detectors based on different physical-chemical principles which makes it extremely versatile. This technique is routinely used in the pharmaceutical field, in biochemical and biomedical applications, as well as for quality control. More recently the possibility to hyphenate HPLC with the mass spectrometer, significantly increased the sensitivity and selectivity obtained thus explaining the wide spread of LC-MS instrumentation in analytical chemistry laboratories particularly in the pharmaceutical, environmental, and food analysis fields. Only more recently, this technique has spread to forensic analysis, providing a viable alternative to gas chromatography. In recent years, capillary electrophoresis (CE) has been introduced as a new independent separation technique, showing original characteristics in terms of separation mechanisms, speed of analysis, separation efficiency and minimal sample requirements. The hyphenation of CE with MS has been successfully applied in many fields of analytical chemistry and biochemistry combining the high separative efficiency that characterizes the CE with high sensitivity and selectivity brought by the mass detector. Although the geometry of the interfaces are not yet optimized, CE-MS seems to give promising results. The purpose of this study was to explore the possibilities offered by these new liquid phase separation techniques (micro-HPLC and CE) in order to develop new methods for the separation of molecules of forensic and biomedical interest.