Instruments

Mass Spectrometer

Also Known As Mass Spec

Citation Formats

General Reference

Science Atlas. "Mass Spectrometer." Accessed August 30, 2026. https://dev-science.interactiveatlas.org/instruments/mass-spectrometer.

APA Style

Science Atlas. (n.d.). Mass Spectrometer. Retrieved August 30, 2026, from https://dev-science.interactiveatlas.org/instruments/mass-spectrometer

BibTeX

@misc{scienceatlas-mass-spectrometer,
  author = {Science Atlas},
  title = {Mass Spectrometer},
  year = {2026},
  url = {https://dev-science.interactiveatlas.org/instruments/mass-spectrometer},
  note = {Accessed August 30, 2026}
}

A mass spectrometer ionizes a sample, accelerates the resulting ions through electric and magnetic fields, and sorts them by their mass to charge ratio, producing a spectrum that reveals what elements or molecules a sample contains and in what proportions. J.J. Thomson built an early version around 1912 to study positively charged particles, and his student Francis Aston refined it into the modern mass spectrograph by 1919, precise enough to discover that many elements exist as a mixture of isotopes of slightly different mass, work for which Aston received the 1922 Nobel Prize in Chemistry.

Facts

Invented Yearthe subject's own account

1912 1

Measuresthe subject's own account

The mass-to-charge ratio of ions. 1

Operating Principlethe subject's own account

A sample is ionized, and the ions are separated by mass-to-charge ratio as they are accelerated through electric or magnetic fields, with a detector recording the abundance of each ion type to produce a spectrum. 1

Resolutionthe subject's own account

Resolving power varies sharply by analyzer type, from about 1,000 for a quadrupole analyzer to roughly 1 million, and over 2.7 million at mass-to-charge ratio near 400, for Fourier-transform mass spectrometry. 1

Operating Rangethe subject's own account

No single universal mass range applies across analyzer types; electrospray ionization instruments are cited measuring proteins around 200,000 daltons at mass-to-charge values of 600 to 2000. 1

Cross-Tradition Connections

Invented By

Francis Aston

Refined Thomson's device into the mass spectrograph in 1919 and won the 1922 Nobel Prize in Chemistry for it.

Source Mass Spectrometry (Wikipedia)

J. J. Thomson

Built an early positive ray apparatus around 1912 to 13 that sorted charged particles by mass, producing the first mass spectra; his student Francis Aston later refined the device into the modern mass spectrograph.

Source Mass Spectrometry (Wikipedia)