Robert J. Cotter

Cotter was raised in Abington, Massachusetts, and was the oldest of seven children. After being educated at Boston College High School in 1961, he attended the College of the Holy Cross in Worcester, Massachusetts. After graduating in 1965 with a Bachelor of Science (B.S.), he studied under W.S. Koski at Johns Hopkins University. He received his Ph.D. in 1972 and joined the faculty of Towson University and Gettysburg College.

From 1978 until his death in 2012, Robert Cotter was a member of the faculty at Johns Hopkins University in the departments of Pharmacology and Molecular Sciences and Biophysics and Biophysical Chemistry.{{cite web | url=http://www.hopkinsmedicine.org/mams/ | title=Robert Cotter | accessdate=November 21, 2012 | url-status=dead | archiveurl=https://web.archive.org/web/20121117195430/http://www.hopkinsmedicine.org/mams/ | archivedate=November 17, 2012 }}

{{Main article|Reflectron#Gridless Reflectron|l1=Reflectron}}

To increase the mass resolution in time-of-flight mass spectrometry, a reflectron is often employed. Traditional, single-stage or linear reflectrons suffered from a lack of sensitivity and resolving power when ion velocities (and thus kinetic energies were not equal. In MALDI mass spectrometry, metastable ions generated spontaneously after ionization (post-source decay) exhibit a wide spectrum of kinetic energies.{{cite journal | title=Metastable Decay of Peptides and Proteins in Matrix-assisted Laser-desorption Mass Spectrometry |vauthors=Spengler B, Kirsch D, Kaufmann R | journal=Rapid Comm. Mass Spec. | year=1991 | volume=5 |issue=4 | pages=198–202 | doi=10.1002/rcm.1290050412|bibcode=1991RCMS....5..198S }} This is also known to occur during collision-induced dissociation.{{cite book | title=Time-of-Flight Mass Spectrometry: Instrumentation and Applications in Biological Research | publisher=American Chemical Society | author=Cotter, Robert J. | year=1997 | location=Washington, DC | isbn=978-0841234741}} In 1993, Cotter's research group discovered that, using a non-linear electric field, the spread of ion kinetic energies could be compensated, increasing the resolution of time-of-flight mass spectrometers and forming the basis for many modern TOF/TOF mass spectrometers.{{cite journal | title=A curved-field reflectron for improved energy focusing of product ions in time-of-flight mass spectrometry. | author=Cornish T, Cotter, RJ | journal=Rapid Comm. Mass Spec. | year=1993 | volume=7 | issue=11 | pages=1037–1040 | doi=10.1002/rcm.1290071114 | pmid=8280914| bibcode=1993RCMS....7.1037C }}

While he is primarily known for his contributions to the field of time-of-flight mass spectrometry,{{cite journal | title=Time-of-Flight Mass-Spectrometry for the Structural-Analysis of Biological Molecules | author=Cotter, RJ | journal=Anal. Chem. | year=1992 | volume=64 | issue=21 | pages=A1027–A1039 | doi=10.1021/ac00045a002| pmid=1443622 }} his research in the development and application of new ionization techniques for complex biomolecules. These include thermal desorption,{{cite journal | title=Thermally Produced Ions in Desorption Mass Spectrometry |author1=Cotter, RJ |author2=Yergey, AL |name-list-style=amp | journal=Anal. Chem. | year=1981 | volume=53 | issue=8 | pages=1306–1307 | doi=10.1021/ac00231a039}} laser desorption,{{cite journal | title=Laser Desorption Chemical Ionization Mass-Spectrometry | author=Cotter, RJ | journal=Anal. Chem. | year=1980 | volume=52 | issue=11 | pages=1767–1770 | doi=10.1021/ac50061a055}} fast atom bombardment,{{cite journal | title=Comparison of Thermospray and Fast Atom Bombardment Mass-spectrometry as Solution-Dependent Ionization Techniques | author=Fenselau, C, Liberato, DJ, Yergey, JA, Cotter, RJ, Yergey, AL | journal=Anal. Chem. | year=1984 | volume=56 | issue=14 | pages=2759–2762 | doi=10.1021/ac00278a030| pmid=6098190 }} thermospray{{cite journal | title=Adaptation of a Thermospray Liquid-Chromatography Mass-Spectrometry Interface For Use with Alkaline Anion-Exchange Liquid-Chromatography of Carbohydrates |vauthors=Simpson RC, Fenselau CC, Hardy MR, Townsend RR, Lee YC, Cotter RJ | journal=Anal. Chem. | year=1990 | volume=62 | issue=3 | pages=248–252 | doi=10.1021/ac00202a005|pmid=2305955 }} and plasma desorption.{{cite journal | title=Glutathione as a Matrix For Plasma Desorption Mass-Spectrometry of Large Peptides | author=Alai M, Demirev P, Fenselau C, Cotter, RJ | journal=Anal. Chem. | year=1986 | volume=58 | issue=7 | pages=1303–1307 | doi=10.1021/ac00298a008| pmid=3728989 }}

His research into ionization sources also enabled many other discoveries in biomedical sciences. In 1993, he was part of the research team responsible for implicating the 42 amino acid form of the protein Aβ in the pathology of Alzheimer's disease.{{cite journal | title=Beta-Amyloid-(1-42) is a Major Component of Cerebrovascular Amyloid Deposits – Implications for the pathology of Alzheimer-Disease | author=Roher, AE, Lowenson, JD Clarke, S, Woods, AS, Cotter, RJ, Gowing, E, Ball, MJ | journal=Proc. Natl. Acad. Sci. USA | year=1993 | volume=90 | issue=22 | pages=10836–10840 | doi=10.1073/pnas.90.22.10836 | pmid=8248178 | pmc=47873| bibcode=1993PNAS...9010836R | doi-access=free }}

{{Main article|ExoMars rover#Pasteur instrument suite|l1=Pasteur instrument suite}}

The Mars Organic Molecule Analyzer (MOMA) project is part of a collaboration to search for potential signatures of Martian life. Cotter was a deputy principal investigator and responsible for the design and development of a low-power, ion trap-time-of-flight mass spectrometer to be deployed with the ESA ExoMars rover. However, in February 2012, NASA cancelled its participation in the rover and defunded projects related to it.{{cite web | url=http://www.nasa.gov/mission_pages/mars/news/exo20100826.html | title=Tracing the Big Picture of Mars' Atmosphere | accessdate=November 21, 2012}} By November 2012 NASA reestablished the funding for the US part of MOMA.{{cite journal | url = http://www.spaceflightnow.com/news/n1211/21exomars/#.ULCc6GfWE64 | title = European states accept Russia as ExoMars partner| author= STEPHEN CLARK|publisher =SPACEFLIGHT NOW| date= November 21, 2012}}

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{{Recipients of the Distinguished Contribution in Mass Spectrometry Award}}

{{Field and Franklin Award}}

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Category:20th-century American chemists

Category:Mass spectrometrists

Category:1943 births

Category:2012 deaths

Category:College of the Holy Cross alumni

Category:Johns Hopkins University alumni