High Resolution Mass Spectrometry Improves Data Quantity and Quality as Compared to Unit Mass Resolution Mass Spectrometry in High-Throughput Profiling Metabolomics

includes the precursor unit mass profile (including adducts, in-source fragments, isotopes, etc.), retention time, and MS/MS spectra on the ions from the authentic standard. Experimental data is then searched against this library and detected compounds are rapidly identified. This multi-criteria authentic standard library dramatically diminishes the need for HRAM data for compound identification since the multiple data streams (i.e., mass, retention and fragmentation pattern), provide the needed specificity to make identifications. Using this library, our methodology monitors each sample for over 3200 endogenous and exogenous metabolites. In addition, this library includes over 4000 chemicals whose identities have yet to be determined (unknowns). It is important to note that while this library consists of such a large number of compounds, not all compounds are detected in each experimental analysis on a routine basis. Many are matrix specific; for example, found in cells or urine only. Others may be species specific or disease specific. The field at large has yet to agree on the number of metabolites that are routinely detected in mammalian or plant species and there is much debate about how many should, can or will ultimately be detectable; estimates range from the low hundreds to many thousands