Specific action concept

{
  "id": "MLC-T-CHM-013581",
  "term": "Specific action concept",
  "field": "Chemistry",
  "definition": "A working assumption in radiotracer studies that a radioactive isotope of an element behaves exactly like the stable isotope it labels, in both chemical and biological processes. On that basis, radioactivity measured in a compartment or compound is taken to report the amount and movement of the stable element, for example carbon-14 standing in for ordinary carbon. The assumption is weakest for hydrogen, where tritium differs enough in mass from protium to show measurable kinetic isotope effects.",
  "synonyms": [
    "specific activity concept"
  ],
  "subject": "Chemistry and Human Health",
  "references": [
    "PAC, 2009, 81, 829. 'Glossary of terms used in ecotoxicology (IUPAC Recommendations 2009)' on page 949 (https://doi.org/10.1351/PAC-REC-08-07-09)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/specific-action-concept/"
}