Chemical Reference Libraries are Essential for Structural Elucidation in Metabolomics

摘要

Accurate mass and MSn fragmentation data is often insufficient to generate a unique chemical structure. The incorporation of a chemical reference library in the structural elucidation process allows for a narrowing of possible chemical structures by monitoring characteristic fragmentation patterns with known compounds and monitoring diagnostic loses from compounds. The use of chemical standards in spiking experiments can generate data that is consistent with a given structure. As the number of degrees of confirmation increases, the probability of an incorrect chemical's structure decreases. Similar compounds in the chemical reference library may provide specific clues such as functional groups present or modifications (i.e., oxidation, reduction, methylation, etc.) that have occurred to an unnamed chemical that is similar to a chemical reference library entry. Chemical reference libraries can also help resolve questions concerning isobaric compounds.