2D Mass Spectrometry: A Novel Method to Analyze Complex Samples

Traditional tandem mass spectrometry, an analytical technique that isolates a precursor ion then fragments it to obtain structural information, is a method extensively used in analytical chemistry. Coupling different separation methods, like LC and GC, can help study complex mixtures that may be difficult with MS/MS alone. However, the isolation step requires a sufficient signal threshold of the precursors, preventing low signal ions that may hold important structural information from being fragmented. It is also difficult to isolate a single precursor if there is another ion with a very close m/z value. 2D mass spectrometry solves these problems by fragmenting all the precursor ions without prior isolation and correlating the precursor ions and their respective fragment ions. In the FTICR, the modulation of the cyclotron radius prior to fragmentation allows the correlation of the precursor ions and the fragment ions. The bottom up analysis of cytochrome c with 2D MS is compared to MS/MS bottom up analysis, and the bottom up and top down analysis of calmodulin via 2D MS is explored. Results show a promising new technique complementary to traditional MS/MS as well as more areas of research to make 2D MS more accessible and applicable.