LC-MS applications in Pharmaceutical Analysis, Bioanalysis and Proteomics

Liquid Chromatography tandem Mass Spectrometry (LC-MS) is a powerful tool available to scientists with multidisciplinary applications. In this thesis, LC-MS technique had a key role to perform exciting experiments giving back an outstanding contribute to each project caught up. Different LC-MS instruments were involved. We worked with HPLC and UHPLC systems operating with micro- or nano-flow rates. At the same time, various MS analyzers working in different scan modes (full MS, MS2, MS3, SRM, MRM and DDA) were chosen depending by the expected results. The projects addressed by this thesis were: (1) The identification and characterization of troxerutin degradation products by chemical stability studies. (2) The quantitative evaluation of Adenosine 4'-tetraphosphate (Ap) and Nicotinamide phosphoribosyltransferase (NAMPT) related compounds in B16 cells and in C57BL/6 healthy male mice plasma. (3) The quantitation of serotonin extracellular levels in murine neural progenitor cells. (4) The Identification, quantification and investigation of phosphorylation as post translational modification on NAMPT in B16 cells. For each work, the experimental conditions, the sample handling and preparation, the LC-MS set up and the data analysis were developed and successfully applied. In conclusion, we demonstrated the versatility, reproducibility and robustness of the LC-MS technique through various chemical and biological applications.