MRI: Acquisition of a Next-Generation High-Resolution Mass Spectrometer with Ion Mobility Separation

This award is supported by the Major Research Instrumentation and the Chemistry Research Instrumentation programs. The University of Texas San Antonio is acquiring a high-resolution quadrupole-time-of-flight mass spectrometer (Q-TOF MS) with ion mobility (IM) separation and an atmospheric pressure chemical ionization source to support Dr. Wendell Griffith and colleagues Michael Doyle, Aimin Liu, Francis Yoshimoto and Audrey Lamb (from Kansas University).

In general, mass spectrometry (MS) is one of the key analytical methods used to identify and characterize small quantities of chemical species in complex samples. Ion mobility is a method that separates gas phase ions based on their interaction with a collision gas depending on their masses. First the ions are quickly separated as they move on a buffer gas and then introduced into the mass analyzer.

It is useful to analyze complex samples in proteomics and metabolomics. In the time-of-flight (TOF) method of mass spectrometry, the mass-to-charge ratio of an ion is determined by the way in which ions are accelerated by an electric field of known strength. The velocity of the ion depends on the mass-to-charge ratio (heavier ions of the same charge reach lower speeds).

The time that the ions take to reach a detector at a known distance is measured. This time depends on the velocity of the ion, and therefore is a measure of its mass-to-charge ratio. From this ratio and known experimental parameters, the ion can be characterized.

The acquisition strengthens the research infrastructure at this Hispanic Serving Institution and regional area. The instrument broadens participation by involving diverse students with this modern analytical technique. It is also used by collaborators at primarily undergraduate institutions in South Texas as well as the University of Kansas.

The award of the IM-Q-TOF MS system is aimed at enhancing research and education at all levels. It is especially useful for studying opine metallophore synthetic pathways in bacterial with the aim of developing antimicrobial drugs; the opine metallophores are low molecular weight compounds found in plant tumors which extract metal ions from the host.

The instrumentation is also used for understanding the effect of intramolecular crosslink cofactors to dioxygenase enzyme structure and function, as well as expanding knowledge of the biosynthesis of artemisinin, an endoperoxide containing plant natural product used to treat malaria. The instrument also serves researchers developing new catalytic approaches to stereoselective syntheses of structurally complex organic compounds and those trying to gain deeper insight into the kinetics of insect odorant reception.

The mass spectrometer is also essential to characterize lipids that might be associated with Alzheimer's disease and chronic pain.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.