Close-up view of the interior of a Bendix MA-2 Time-of-Flight Mass Spectrometer showing the mercury diffusion pumping system contained in the analyzer console. The Time-of-Flight Mass Spectrometer (TOFMS) was the flagship analytical instrument of the Bendix Corporation.

Mass spectrometry is an analytical technique used to identify qualitatively and quantitatively the atomic and molecular composition of inorganic and organic materials by sorting ions according to their mass-to-charge ratios. Mass spectrometers consist of four basic parts: a handling system used to introduce the unknown sample into the equipment; an ion source, in which a beam of particles characteristic of the sample is produced; an analyzer that separates the particles according to mass; and a detector, in which the separated ion components are collected and characterized.