Accurate mass

Categories: mass spectrometry

Definition

Experimentally determined mass of an ion of known charge. Can be used to determine elemental composition to within limits defined by both the accuracy and precision of the measurement if the ion mass is low enough to limit the number of formulaic possibilities. Note: Accurate mass and exact mass are not synonymous. Accurate mass refers to a measured mass, and exact mass refers to a calculated mass via summation of the exact masses of the constituent atoms.