| The chemical characterization of biological molecules is very important to gain insights into the functions of biological systems. Over the past two decades mass spectrometry has become one of the most widely used tools in analytical chemistry. Electrochemistry has a long history in the characterization of redox reactions of many biological molecules. The purpose of this work was to use mass spectrometry combined with gas chromatography (GC/MS) in the detection of 21 protein amino acids, and electrochemistry and mass spectrometry to investigate the reductive activation of the anticancer drug, mitomycin C.;In work study the one-step derivatization of amino acids was achieved using trifluoroacetic anhydride (TFAA) and its homologs, and trifluoroethanol (TFE) and its homologs. The electrophilic derivatives formed are highly sensitive to detection by electron capture negative ionization MS (ECNI-MS). The one step formation of derivatives has an advantage over techniques previously used. Also, the potential for the formation of cyclic derivatives is another benefit, as these derivatives could yield abundant molecular anions under ECNI conditions providing sensitivity and selectivity for detection by selected ion monitoring.;Electrochemistry on-line with mass spectrometry (EC/MS) has been shown to model the in vivo enzymatic oxidation of purines. In this work EC/MS was used to reductively activate mitomycin C by electrochemistry and to detect by on-line mass spectrometry the adducts formed between the electrophilic intermediate of mitomycin C and the DNA base, guanosine.;An electrochemical cell based on a thin-layer design was also developed. This cell allows for the resurfacing and replacement of the electrode which is a major advantage over the electrochemical cell used previously with on-line EC/MS. Off-line electrochemical investigations of mitomycin C in different solvents and at different graphite electrodes were also performed. These experiments were important to find out the ideal parameters for the on-line electrochemical reduction and mass spectrometric detection of mitomycin C. |
