Sarah Trimpin

Sarah Trimpin



313-577-8822 (fax)

 Chem 373


Sarah Trimpin

Research Interest/Area of Expertise

  • Total solvent-free mass spectrometric analysis of solubility-restricted, complex materials (membrane proteins, lipids, etc.) by coupling solvent-free ionization (MALDI, MILD ) to gas phase separation (IMS) methods.


Our research seeks to develop a fundamental understanding of a newly discovered process that brings into question what is currently taught relative to ionization methods in mass spectrometry. This extremely simple ionization method for use in mass spectrometry requiring only exposure of matrix/analyte to vacuum is applicable to high throughput analyses, surface analysis, field portable mass spectrometers, and unskilled operation. The interdisciplinary nature of our group with collaborators from academia and industry and across nations promotes training of scientists in multidisciplinary research at the interface of analytical, biological, and materials sciences. The postdoc and graduate students directly involved gain expertise in fundamental, instrumentation and applications of an unprecedented ionization method for use in MS. It provides both graduate and undergraduate students hands-on experience using cutting-edge research equipment to solve problems and thus develop their own scientific thinking and problems solving skills. We are committed to using the excitement of research discovery to enhance the interests of all students in science and in particular as a role model for women and undergraduates interested in the physical sciences.

The inventors of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) MS shared a portion of the 2002 Nobel Prize in Chemistry because of the importance of these ionization methods in advancing science. In spite of the importance, the ionization mechanisms of these methods are not yet fully understood. We have discovered an ionization process that uses a matrix, similar to MALDI, but produces ions having charge states nearly identical to ESI. This novel ionization process is initiated by heat or vacuum, and does not require either voltage or a laser used in ESI and MALDI, respectively. Understanding how ESI-like mass spectra can be obtained from a solid surface in vacuum without laser ablation, or applied heat or voltage, and using a matrix compound that has no acidic hydrogen atoms, is of broad scientific interest and has the potential to unlock the mysteries surrounding ionization processes capable of ionizing nonvolatile compounds.

The theme to our current research is to study fundamentals of a newly discovered method for transferring molecules, regardless of size or volatility, from the solid state in a small molecule matrix to gas-phase ions for analysis by MS. The method only requires exposure of the sample in matrix to the vacuum inherent with all mass spectrometers. The ability to transport molecules at least as large as bovine serum albumin (67 kDa) into the gas phase as highly protonated ions without input of external energy is unprecedented in science, analytically important, and of fundamental interest in understanding ionization processes. Knowledge of the fundamentals of how this process occurs will advance our scientific understanding for all ionization methods whereby nonvolatile molecules are converted from the solid or liquid states to gas-phase ions, and provide guidance on how to increase the efficiency of ionization. Using the same analyte solutions and instrumentation designed for ESI or MALDI MS, under similar conditions, the newest ionization method, termed matrix assisted ionization vacuum, is already at least as sensitive as ESI or intermediate pressure MALDI, and offers the ability to rapidly interrogate specific surface features by simply applying a matrix solution to the surface defect and exposure to the vacuum at the atmospheric pressure inlet of the mass spectrometer. Improved ionization will ultimately minimize the surface area that can be interrogated, possibly reaching single cell analyses in the future. The simplicity of the new ionization method is particularly advantageous, and holds promise for novel applications for which currently trained personnel are needed. 


Education – Degrees, Licenses, Certifications

  • Diplom Universität Konstanz, 1999 (Germany)
  • Doctor rerum naturalium Max-Planck-Institute for Polymer Research (degree granting institution: Universität Mainz), 2002 (Germany)
  • Postdoctoral Fellow, Oregon State University/Oregon Health&Science University, 2002-2006
  • Research Associate, Indiana University, 2007-2008

Selected Publications


  1. Trimpin, S.* "Magic" Ionization Mass Spectrometry. J. Am Soc. Mass Spectrom. 27(1), 4-21, 2016. (invited Critical Insight Article: these aricles are by invitation to experts in a specific field).


  2. Fischer, J.L., Lutomski, C.A., El-Baba, T.J., Siriwardena-Mahanama, B.N., Weidner, S.M., Falkenhagen, J., Allen, M.J., Trimpin, S.,* Matrix-Assisted Ionization-Ion Mobility Spectrometry-Mass Spectrometry: Selective Analysis of a Europium-PEG Complex in a Crude Mixture. J. Am. Soc. Mass Spectrom. 26(12), 2086-2095, 2015.


  3. Chakrabarty, S., DeLeeuw, J.L., Woodall, D.W., Jooss, K., Narayan, S.B., Trimpin, S.,* Reproducibility and Quantitation of Illicit Drugs using Matrix-Assisted Ionization (MAI) Mass Spectrometry. Anal. Chem. 87(16), 8301-8306, 2015.


  4. Foley, C.D., Zhang, B., Alb, A.M., Trimpin, S.,* Grayson, S.M.,* The Use of Ion Mobility Spectrometry-Mass Spectrometry to Elucidate Arm-Dispersity within Star Polymers, ACS Macro Letters 4(7), 778-782, 2015.


  5. Wang, B., Dearring, C.L., Wager-Miller, J., Mackie, K., Trimpin, S.,* Drug Detection and Quantification Directly from Tissue using Novel Ionization Methods for Mass Spectrometry. European J. Mass Spectrom. 21(3), 201-210, 2015. (Invited contribution to special 20th Anniversary Issue)


  6. Woodall, D.W., Wang, B., Inutan, E.D., Narayan, S.B., Trimpin, S.,* High-throughput Characterization of Small and Large Molecules Using Only a Matrix and the Vacuum of a Mass Spectrometer. Anal. Chem. 87(9), 4667-4674, 2015.


  7. Trimpin, S.,* Lutomski, C.A., El-Baba, T.J., Woodall, D.W., Foley, C.D., Manly, C.D., Wang, B., Liu, C.W., Harless, B.M., Kumar, R., Imperial, L.F., Inutan, E.D., Magic Matrices for Ionization in Mass Spectrometry. Int. J. Mass Spectrom. . 377(SI), 532-545, 2015. (Invited contribution to 100th year of Mass Spectrometry special issue)