Abstract
A fixed ligand (FL) version of the kinetic method was applied to rapid, simple, and accurate chiral analysis of DOPA, which is an important drug used for treatment of Parkinson's disease. Singly charged clusters containing the transition metal ion Cu(II), pyridyl ligands which serve as a fixed ligand, some amino acid as a reference, and the analyte DOPA were generated by electrospray ionization. The cluster ion of interest was mass-selected, and the kinetics of its competitive unimolecular dissociations was investigated in an ion trap mass spectrometer. The chiral selectivity (R(chiral)), the ratio of the two fragment ion abundances when the cluster contains one pure enantiomer of the analyte expressed relative to that for the other enantiomer, varies with fixed ligands, references, and transition metals. Chiral discrimination was optimized in 1,10-phenanthroline as a FL, L-Phe and L-Pro as a reference, and Cu(II) as a central metal ion. Quantitative determinations of the enantiomeric composition of DOPA were achieved using two-point calibration curves. The linear relationship between the logarithm of the fragment ion abundance ratio (ln R) and enantiomeric compositions (ee%) of the DOPA allows the determination of the chiral purity of enantiomeric mixtures.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.