A Life Measured in Peaks: Honoring Alan George Marshall (1944–2025)

Alan G. Marshall

Alan George Marshall, a visionary scientist whose pioneering work redefined the frontiers of analytical chemistry, passed away on June 6, 2025, in Tallahassee, Florida. He was 81. As co-inventor of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), Marshall's transformative contributions provided scientists with unprecedented tools to probe the molecular world—from the innermost workings of proteins to the outer reaches of the solar system.

Over the course of a five-decade career, Marshall became a towering figure in analytical chemistry, celebrated not only for his revolutionary science but also for his exceptional mentorship, professional leadership, and human warmth.

A Scientific Foundation Built Early

Born in Bluffton, Ohio, in 1944 and raised in San Diego, Marshall initially entered Northwestern University's pioneering six-year medical program. But chemistry soon claimed his full attention, and he graduated with honors in 1965 with a B.A. in Chemistry. He earned his PhD in Physical Chemistry from Stanford University in 1970 under the guidance of John Baldeschwieler. A postdoctoral appointment followed, leading to a faculty position at the University of British Columbia (1–7).

It was there, in 1973, that Marshall and collaborator Melvin B. Comisarow co-invented FT-ICR MS—a technique that would transform the capabilities of modern mass spectrometry.

Redefining Mass Spectrometry: FT-ICR

FT-ICR MS merged the precision of ion cyclotron resonance with the computational power of Fourier transform analysis. The result was an analytical tool of remarkable resolution and sensitivity, capable of distinguishing thousands of distinct chemical species within complex mixtures. Whether used to characterize crude oil (in what Marshall coined “petroleomics”), study protein structure, or analyze lunar and meteoritic material, FT-ICR opened new dimensions in molecular analysis (1–7).

This work earned mention in John Fenn’s Nobel Prize address (2002) and led to Marshall’s setting of a world record for identifying the greatest number of unique molecular species in a single crude oil sample.

Academic Excellence and National Impact

Marshall joined The Ohio State University in 1980, directing its Chemical Instrument Center. In 1993, he moved to Florida State University (FSU) as the Robert O. Lawton Professor of Chemistry and Biochemistry. There, he also served as founding director of the Ion Cyclotron Resonance Program at the National High Magnetic Field Laboratory (MagLab)—a globally recognized hub for ultrahigh-resolution mass spectrometry (6,7).

Until his retirement in 2024, he remained Chief Scientist at MagLab, sustaining its position at the cutting edge of instrumentation and discovery.

Legacy of Mentorship

Over his lifetime, Alan Marshall mentored more than 150 PhD students and postdoctoral researchers, shaping future generations of chemists. His students described him as exacting yet generous, scientifically rigorous yet deeply human. At least five alumni honored him by naming their sons “Alan”—a personal tribute to the impact he had on their lives (6,7).

Marshall's scholarly contributions were as profound as his mentorship. His 659 peer-reviewed publications, more than 63,000 citations, and Hirsch index of 127 place him among the top 20 most-cited chemists of his time (4–7).

Honors and Service

Marshall received nearly every major award in analytical chemistry and mass spectrometry, including (1–7):

• Distinguished Contribution Award, American Society for Mass Spectrometry (1999)
• Thomson Medal, International Mass Spectrometry Foundation (2000)
• Chemical Pioneer Award, American Institute of Chemists (2007)
• Field-Franklin Award and Nichols Medal, American Chemical Society (1995, 2012)
• Pittsburgh Analytical Chemistry Award (2012)
• Herty Medal, ACS Southeastern Region (2003)

He was elected fellow of the American Chemical Society (ACS), American Physical Society (APS), American Association for the Advancement of Science (AAAS), Society for Applied Spectroscopy (SAS), and American Academy of Arts and Sciences. In 2025, he was named to the inaugural class of American Society for Mass Spectrometry (ASMS) Fellows (4–7)..

Marshall also served as President of the American Society for Mass Spectrometry (2004–2006) and contributed to editorial boards for journals including Analytical Chemistry, Mass Spectrometry Reviews, and Journal of the ASMS.

The Man Behind the Peaks

Despite his accolades, Marshall remained deeply grounded. He was known for his humility, incisive wit, and quiet generosity. He relished crossword puzzles and once played on a Canadian national champion volleyball team. A lifelong lover of nature, he supported conservation causes, including the Nature Conservancy and the National Audubon Society (1–3). Marshall was married for 56 years to Marilyn Marshall, who passed away in 2021.

A Resonant Legacy

Alan George Marshall didn’t just advance mass spectrometry—he transformed it. He provided tools to see the invisible, methods to measure the immeasurable, and a spirit of inquiry that continues to animate the work of researchers worldwide.

His memory lives on in the scientific instruments that bear his influence, the students who carry forward his teachings, and the colleagues who remember his friendship. In every spectrum traced to FT-ICR and every young scientist he inspired, his legacy continues to resonate.

Marshall showed us what it means to lead with both precision and compassion. His life was, quite literally, a life measured in peak contributions and accomplishments (1–7).

References and Further Reading

(1) American Society for Mass Spectrometry Oral History Project Home Page. Available at: https://www.asms.org/about/history/oral-history-project (accessed 2025-06-17).

(2) Alan George Marshall Obituary Home Page. Available at: https://www.tallahassee.com/obituaries/psar1204956 (accessed 2025-06-17).

(3) Alan G. Marshall Wikipedia Page. Available at: https://en.wikipedia.org/wiki/Alan_G._Marshall (accessed 2025-06-17).

(4) Alan G. Marshall Google Scholar Page. Available at: https://scholar.google.com/citations?user=FvFEsEgAAAAJ&hl=en (accessed 2025-06-17).

(5) National High Magnetic Field Laboratory Alan G. Marshall Page. Available at: https://nationalmaglab.org/staff/?name=AlanMarshall (accessed 2025-06-17).

(6) University of Cincinnati Alan Marshall Page. Available at: https://www.artsci.uc.edu/content/dam/refresh/artsandsciences-62/docs/marshall.pdf (accessed 2025-06-17).

(7) National High Magnetic Field Laboratory Page. Alan Marshall: A scientist and a Gentleman. Available at: https://nationalmaglab.org/careers/meet-our-scientist-staff/alan-marshall-a-scientist-and-a-gentleman/ (accessed 2025-06-17).