The Xevo G2-S is a high mass resolution Q-ToF MS/MS instrument. It is capable of performing high resolution accurate mass MS and MS/MS analyses and is most commonly used for accurate mass measurements of purified biomolecular compounds in solution, using an ESI ion source. the ion source may also be operated as an APCI ion source for mass spectral analysis of medium to high polarity compounds. The instrument may also be equipped with an ASAP ion source for the analysis of solids or residues. The instrument is operated on on a “self-service” basis by the facility manager due to its complexity of operation. This instrument is located in Room B23, Remsen Hall.