Mass Spectrometers

Liquid Chromatography Mass Spectrometry systems (LC-MS)

Dr. Albert J. Fornace Jr was recognized by Waters Corporation as a leader in metabolomics research and Georgetown University became part of the Waters Center of Innovation.

All the mass spectrometry instruments are coupled to an Ultra Performance Liquid Chromatography (UPLC). The Premier and the Xevo G2 are utilized for profiling and tandem mass spectrometry, while the Xevo TQ-S is utilized for sensitive and absolute quantification. The newest addition to the spectrometers includes the Synapt G2-Si, allowing for superior characterization of complex molecules with the added ability of ion mobility spectrometry.

Gas Chromatography Mass Spectrometry systems (GC-MS)

GC-MS is a useful analytical technique that combines mass spectrometry and gas chromatography for the accurate measurement of volatile organic and inorganic compounds. Manufacturer supplied software with built-in spectral libraries makes GCMS makes for easy identification of compounds. Our Metabolics Shared Resources core has recently acquired a new Leco Pegasus HT GC-TOFMS, which has expanded the range of metabolites that we can assess.

With previous LC-MS analysis, leucine and isoleucine were indistinguishable due to similar elution times. GC-MS has allowed us to separate the two molecules, as can be seen in the figure, and therefore utilize the now known differences in levels to translate into specific methods with LC-MS. In addition, the complementary nature of GC-MS has allowed us for the full assessment of energy metabolism pathways, particularly the Tricarboxylic acid (TCA) cycle, and the full spectrum of amino acids.