Mass Spectrometry & Proteomics Core

This instrument is equipped with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources and is used for the majority of HRMS analyzes. A direct insertion probe is available for the APCI source for the analysis of solid compounds and those with limited solubility in MS-friendly solvents.

For the HRMS service, mass analysis can be carried out for most classes of molecules including small organic molecules (with molecular weight < 1000 g/mol); larger molecules (with molecular weight > 1000 g/mol); biomolecules like peptides, proteins, lipids, carbohydrates; and metal-ligand complexes just to list a few examples. For this service, high resolution and highly accurate mass measurement can be used to predict and/or confirm the chemical composition (chemical formula) for synthetic products, which is a requirement for publication in a large number of journals.

For increased confidence, tandem mass spectrometry (MS/MS) can be applied to produce structurally diagnostic fragments, which can be used to confirm the structures of compounds, determine various functional groups/substituents that may be present, and even distinguish between structural isomers.

Proteomics services are largely conducted using our ultrahigh-resolution Orbitrap mass spectrometer. Analyses can be as simple as the sequencing of peptides to confirm sequences or possible modifications. The most popular service is the identification of unknown proteins or confirmation of recombinant protein expression products. The MSPC does all steps of the sample prep and LC-MS analysis processes including SDS-PAGE, proteolysis, LC-MS/MS, bioinformatics analysis, and data reporting in a user-suitable format. Using these proteomics approaches, we can also assist with the confirmation of residue-specific modifications and the identification of some types of posttranslational modifications.

Our LC-MS services focus on analyses using our triple quadrupole LC-MS system for quantitative analyses of small molecules. Some examples of the types of analyses that we have recently conducted are quantitation of analytes like lipids, drugs, drug metabolites, reaction intermediates, etc. in media like water, serum, plasma, synthetic reaction mixtures, extracts, etc. for a variety of applications. Most of these approaches require the use of an internal standard where low ppb (part per billion) detection limits can be achieved. The MSPC does provide support for method development and sample preparation.

The timsTOF Pro II is a high-resolution, high mass accuracy mass spectrometer that is capable of all of the services described for the maXis Q-TOF instrument. In addition to these, this instrument has trapped ion mobility, which enables the separation, analysis and in some cases quantitation of structural isomers and conformers. High-resolution ion mobility separation (with R > 200), along with resolving isomeric and isobaric species, also provides clean fragmentation spectra which are easily correlated with their precursor ions to definitively and conclusively support compound identification. Additionally, the ion mobility separation can provide physical property data on compounds like their collisional cross section (CSS).