METHOD OF MASS ANALYSIS OF TARGET MOLECULES IN COMPLEX MIXTURES

摘要

The present invention is a method for performing a mass spectrometric ana lysis of analytes in a complex mixture. In particular, samples containing un known analytes are analyzed by MS/MS to identify portions of a molecule of i nterest that has been labeled with a selected isotope. Ionization and detect ion identify a characteristic isotope shift in real time based on a selectiv e precursor ion scan that in turn identifies precursor masses that also cont ain the isotopic shift. From the precursor ion scan, precursor masses are id entified for further mass spectrometric analyses. The method of the inventio n is preferably performed in real time such that the precursor ion scan simu ltaneously identifies target precursor ions and identifies precursor masses for further analyses.