mass spectroscopy

from WordNet (r) 3.0 (2006)

mass spectroscopy
    n 1: the use of spectroscopy to determine the masses of small
         electrically charged particles

from The Collaborative International Dictionary of English v.0.48

mass spectrometry \mass spectrometry\ mass spectroscopy \mass
spectroscopy\n.
   1. (Physics, Chemistry) A method for identifying chemical
      composition of substances by use of a {mass spectrometer}.
      [PJC]