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This web page's content and links are no longer actively maintained. It is available for reference purposes only. NASA Official: Dr. Paul Mahaffy

Gas Chromatograph Mass Spectrometer

Mass Spectrometer

“A mass spectrometrist is someone who figures out what something is by smashing it with a hammer and looking at the pieces."

A mass spectrometer produces ions (charged particles) from chemical substances and then uses electric and/or magnetic fields to measure the mass (or weight) of the ions. Using the mass and relative abundance of ions in a mass spectrum, scientists can determine the molecule’s structure and elemental composition.

There are several different types of mass spectrometers: time-of-flight, neutral, and ion, to name a few. The mass spectrometer on the Huygens probe is a quadrupole mass spectrometer. Scientists chose to build a quadrupole mass spectrometer because it could withstand the extreme temperatures of space and the harsh vibrations experienced during the spacecraft launch.

All mass spectrometers, regardless of their specific type, have three basic parts. Below is a schematic of a quadrupole mass spectrometer:

Quadrupole Mass Spectrometer Schematic

Quadrupole Mass Spectrometer Schematic
  1. Source: where the chemical samples are taken in and (if necessary) converted to ions
  2. Analyzer: where the ions are separated according to mass
  3. Detector: where the separated ions produce a signal that can be interpreted by scientists

Next: MS Source - Leaks

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Mass spectrometer image courtesy of University of Arizona, Department of Chemistry