J. Mitchell Wells

Current Status:

 

Research Scientist, Griffin Analytical technologies, Inc., West Lafayette, IN

Education:    

                         

Purdue University, West Lafayette, IN 47907    1995-2000

Ph.D. in analytical chemistry, emphasizing mass spectrometry and other analytical instrumentation, under the direction of Prof. R. Graham Cooks

G.P.A. 3.77 on 4.0 scale

Monmouth College, Monmouth, IL 61462    1991-1995

          B.A. in Chemistry

G.P.A. 3.87 on 4.0 scale

6 month research internship at Oak Ridge National Laboratory

 

Employment: 

 

Purdue University, West Lafayette, IN 47907    March 2000-present

Postdoctoral associate for Prof. Scott A. McLuckey in the Department of Chemistry 

Purdue Univ. Department of Chemistry    June 1995-March 2000
Teaching Assistant for:

          Chemistry 115: general chemistry for engineering majors

Chemistry 111: general chemistry for nursing, agricultural, and other non-science majors.

          Chemistry 624: Graduate level course on particle spectroscopy

 

Research Assistant-Purdue Univ. Department of Chemistry

This period includes a two month internship at Finnigan Corporation in San Jose CA, from October to December, 1997

 

Research Experience:

 

Thesis Research at Purdue University under Prof. R. Graham Cooks.

          

          Thesis Title "Effects of Electrode Geometry on Quadrupole Ion Trap Performance"

      Enhancement in the performance and applicability of quadrupole ion trap mass spectrometers was achieved through variation of the physical structure of the ion trap. Improvements in mass measurement accuracy were pursued through the study of chemical mass shifts, i.e. large, compound-dependent inaccuracies known to occur in ion traps with non-optimized geometry and believed to be related to ion structure. Experiments and computer simulations were used to elucidate the cause of these shifts and methods to remove them. Use of the chemical mass shift for isomer distinction was demonstrated. The performance of cylindrical ion traps (CITs) operated in the mass-selective instability mode was characterized for the first time to test the suitability of this simplified geometry for miniature instrument applications. The performance of the device was optimized by experimental variation of the electrode geometry guided by electric field calculations, and performance comparable to standard hyperbolic ion traps was achieved. Non-destructive, image current detection of ions in a CIT was also reported.

 

Postdoctoral Research with Professor Scott A. McLuckey

      Analysis of high mass biomolecules using electrospray ionization mass spectrometry is being pursued with novel ion/ion reactions which remove charge state ambiguity that arises from the multiple charging which is characteristic of electrospray ionization. Ion/ion reactions can be used to reduce all ions to singly-charged ions, and so simplify interpretation of protein mixture spectra, allowing such mixtures to be analyzed directly with the mass spectrometer without the need for prior time-consuming separation via, for example, gel electrophoresis. Ion-ion reactions can also be used to simplify interpretation of product ion spectra resulting from tandem mass analysis of multiply-charged protein ions, thereby yielding protein sequence information.

 

Publications:

 

1.      S.A. Lammert and J.M. Wells, "Experimental Investigation into the Performance of Ion Traps Using Air versus Helium as the Buffer Gas" Rapid Commun. Mass Spectrom. 10, 361 (1996).

 

2.     J.M. Wells, E.R. Badman, R.G. Cooks, "A Quadrupole Ion Trap of Cylindrical Geometry Operated in the Mass Selective Instability Mode" Anal. Chem. 70, 438 (1998).

 

3.    E.R. Badman, J.M. Wells, H.A. Bui, R.G. Cooks, "Fourier Transform Detection in a Cylindrical Quadrupole Ion Trap" Anal. Chem. 70, 3545 (1998).

 

4.     L.A. Gill, J.M. Wells, G.E. Patterson, J.W. Amy, R.G. Cooks, "Resolution of Isobaric and Isomeric Ions Using Chemical Shifts in an Ion Trap Mass Spectrometer" Anal. Chem. 70, 4448 (1998).

 

5.   J.M. Wells, R.G. Cooks, "There Are No New Scans: Comment on 'A New Scan Mode for the Identification of Multiply Charged Ions' by B.A. Thomson and I.G. Chernushevich, Rapid Commun. Mass Spectrom. 12, 1323 (1998)" Rapid Commun. Mass Spectrom. 8, 752 (1999).

6.      E.R. Badman, G.E. Patterson, J.M. Wells, R.G. Cooks, "Differential Non-Destructive Image Current Detection in a Fourier Transform Quadrupole Ion Trap" J. Mass Spectrom. 34, 889 (1999).

 

7.     J.M. Wells, W.R. Plass, G.E. Patterson, Z. Ouyang, E.R. Badman, R.G. Cooks, "Chemical Mass Shifts in Ion Trap Mass Spectrometry: Experiments and Simulations" Anal. Chem. 71, 3405 (1999).

8.      C. Weil, J.M. Wells, H. Wollnick, R.G. Cooks, "Axial Ion Motion in the Quadrupole Ion Trap Elucidated by DC Pulse Tomography" Int. J. Mass Spectrom. 194, 225 (1999).

 

9.      J.M. Wells, W.R. Plass, R.G. Cooks, "Control of Chemical Mass Shifts in The Quadrupole Ion Trap Through Selection of Resonance Ejection Working Point and RF Scan Direction" Anal. Chem. 72, 2677 (2000).

 

10.    S.A. McLuckey, J.M. Wells, J.L. Stephenson, Jr., D. Goeringer, "Novel Quadrupole Ion Trap Techniques for the Study of Gaseous Macro-ions" Int. J. Mass Spectrom. 200, 137 (2000).

 

11.    J.M. Wells, J.L Stephenson, Jr., S.A. McLuckey, "Charge Dependence of Protonated Insulin Decompositions" Int. J. Mass Spectrom. 203, A1 (2000).

12.    S.A. McLuckey, J.M. Wells, "Mass Analysis at the Advent of the 21^st Century" Chem. Rev. 101, 571 (2000).

 

13.    J.M. Wells, G.E. Reid, B.J. Engel, P. Pan, S.A. McLuckey, "Dissociation Reactions of Gaseous Ferro-, Ferri-, and Apo-cytochrome c Ions" J. Am. Soc. Mass Spectrom. 12, 873 (2001).

 

14.     G.E. Reid, J. Wu, P.A. Chrisman, J.M. Wells, S.A.McLuckey, "Charge State Dependent Sequence Analysis of Protonated Ubiquitin Ions via Ion Trap Tandem Mass Spectrometry" Anal. Chem. In Press. 

 

15.     K.A. Newton, P.A. Chrisman, G.E. Reid, J.M Wells, S.A. McLuckey, "Gaseous Apomyoglobin Ion Dissociation in a Quadrupole Ion Trap: [M+2H]²⁺ to [M+21H]²¹⁺" Int. J. Mass Spectrom. In Press.

 

16.  J.M. Wells, S.A. McLuckey, "Collision Induced Dissociation (CID) of Peptides and Proteins" In  Methods in Enzymology: Biological Mass Spectromtery, A.L. Burlingame, Ed. Academic Press, San  Diego, CA. In Press.

Honors and Awards:  

Monmouth College Presidential Scholarship                      Four year undergraduate scholarship

          1994 Cliff Struthers Hamilton Scholar                               Monmouth College physical science scholarship

1995 American Institute of Chemists Award                     Outstanding senior chemistry major, Monmouth College

1995-96 Brown-Wetherill Scholar                                   Purdue Department of Chemistry award

          1999 Union Carbide Kenan Fellow                                  Union Carbide-sponsored analytical chemistry award

1999 MCM Travel Award                                               Local mass spectrometry discussion group award

          2000 M.G. Mellon Award                                               Purdue Department of Chemistry outstanding graduate student award

References:

           Professor Scott A. McLuckey, Chemistry Department, Purdue University

           Professor R. Graham Cooks , Chemistry Department, Purdue University

           Dr. Stephen A. Lammert , Chemical and Analytical Sciences Division , Oak Ridge National Laboratory

           Professor George Nieman , Chemistry Department, Monmouth College