Accurate mass

{
  "id": "MLC-T-CHM-000118",
  "term": "Accurate mass",
  "field": "Chemistry",
  "definition": "An experimentally determined mass of an ion that is sufficiently precise to allow for the determination of its elemental composition. The required accuracy depends on the mass of the ion and the elements being considered, but it is typically within a few parts per million (ppm) of the exact mass. Unlike nominal mass, which is the integer mass of the most abundant isotope, accurate mass measurement distinguishes between ions with the same nominal mass but different elemental formulas, such as carbon monoxide and molecular nitrogen.",
  "subject": "Analytical Chemistry",
  "see_also": [
    "exact mass"
  ],
  "references": [
    "PAC, 2013, 85, 1515. 'Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)' on page 1519 (https://doi.org/10.1351/PAC-REC-06-04-06)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/accurate-mass/"
}