Delta notation (δ)
Definition
A notation expressing the isotope ratio of a sample relative to an international standard in parts per thousand (per mil, ‰). Positive values mean the sample is heavier than the standard; negative values mean it is lighter.
Related terms
- Epsilon notation (ε)
- Similar to delta but expressed in parts per ten thousand, used for radiogenic systems where variation is very small. Epsilon Nd and...
- MC-ICP-MS (Multi-Collector Inductively Coupled Plasma Mass Spectrometry)
- An instrument that ionises a liquid or laser-ablated sample in an argon plasma at about 8,000 K and simultaneously collects multiple ion...
- Radiogenic isotope
- An isotope produced by radioactive decay of a parent nuclide over geological time. Its abundance in a rock or mineral increases predictably...
- Stable isotope
- An isotope that does not undergo radioactive decay. Ratios of stable isotopes change only through physical or biological fractionation, such as evaporation...
- TIMS (Thermal Ionisation Mass Spectrometry)
- An instrument that ionises a sample deposited on a metal filament and measures ion beam intensities with Faraday collectors. The gold standard...
Explained in
- Isotope Principles for Forensic ProvenanceA notation expressing the isotope ratio of a sample relative to an international standard in parts per thousand (per mil, ‰). Positive values mean the sample i...