Analytical Characterization Exact Mass, Isotope Patterns, Charge State, Stoichiometry, Impurities

Analytical Characterization Exact Mass, Isotope Patterns, Charge State, Stoichiometry, Impurities 

Other signals are present in the spectrum indicating some impurity the signal at m/z 642 corresponds to a doubly-charged ion in which one of the acetal groups has been cleaved. Whether this defect is a result of incomplete synthesis or of acetal cleavage in the spray solvent cannot be determined from the mass spectra alone. 

This analysis can be extended to the other small peaks in the mass spectrum, and one will find some ion resulting from fragmentation of the complexes during ionization. We will not go into detail here, but rather conclude that the careful analysis of the exact mass and the isotope pattern provides information on the elemental composition and with it on the stoichiometry of the complex (e.g. 2 2 

One can deduce the ionization mode and the charge state and gets at least a qualitative idea of the impurities in the sample. With respect to the stoichiometry, the warnings issued above on unspecific binding remain valid, of course. 

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