Mass Frontier uses spectral tree representation for MSⁿ spectra. A spectral tree consists of levels, nodes, node connectors, and node items. The levels symbolize MSⁿ stages starting at n=1. The node connector is a graphical symbol of the precursor m/z value, or the precursor m/z range if the isolation width is included. The node is a holder of node items. The node item stands for the product or calculated spectra of identical precursor m/z value or m/z range or for a chromatogram. Node product spectra, called here parallel spectra, represent spectra acquired at various collision energies and isolation widths, or using wide band activation or they can be zoom spectra, or source CID spectra, or any other spectra that enhance reproducibility in compound identification. If a node contains more than two parallel spectra, the average and composite spectra are automatically calculated. In addition to spectra, each node can contain a chromatogram.

Note: Chemical structures are associated with nodes and not with entire trees. This allows you to assign fragments for product spectra. The top-level node MS¹ should hold the structure of the neutral compound.

Complete trees can be stored in a library and updated at any time. Any complementary information associated with a single stage spectrum or a chromatogram can be associated with a node spectrum or node chromatogram.

Note: If you wish to display or edit complementary information for a particular node spectrum, it must first be selected.

Spectral Tree™ is a trademark of HighChem, Ltd., Slovak Republic