What a stable isotope is
Isotopes are forms of the same chemical element with the same number of protons but a different number of neutrons in the nucleus. Chemically they behave almost identically; they differ in mass and nuclear properties. Stable isotopes are not radioactive. Calcium, for example, has six natural isotopes, from ⁴⁰Ca to ⁴⁸Ca, and tin has ten.
Natural abundance and enrichment
In a natural element the isotopes are mixed in a constant proportion, and the isotope you need is often a fraction of a percent. Enrichment is the share of the target isotope in the material after separation, in atomic percent (at.%). The higher the enrichment, the less the other isotopes interfere in an experiment or in radionuclide production.
| Isotope | In the natural element, ≈ at.% | Enrichment in our catalogue, at.% | Used for |
|---|---|---|---|
| ⁴⁸Ca | 0.19 | 97.60 | superheavy element synthesis |
| ⁶⁴Ni | 0.93 | 96.10 | copper-64 production for PET |
| ¹⁰⁰Mo | 9.7 | 94.30 | technetium-99m, double beta decay |
| ⁷⁶Ge | 7.8 | 94.60 | neutrino physics |
| ¹⁷⁶Yb | 13 | 97.30 | lutetium-177 production |
| ²⁸Si | 92.2 | 99.80 | quantum technologies |
Natural abundance according to IUPAC (rounded). Enrichment according to the producer’s specification; exact lot values are stated in the passport.
Enrichment and chemical purity are different things
A specification usually contains two different figures:
- isotopic enrichment, at.% — the share of the target isotope among the atoms of this element;
- chemical purity, % — how much of other chemical elements (impurities) the material contains.
A material can be enriched to 99 at.% and have a chemical purity of 99.9%, and vice versa. Different tasks depend on different figures: for radionuclide production enrichment and the absence of isotopes that create by-products matter most; for NMR or spectroscopy chemical impurities matter too. That is why our isotope table shows both values.
Chemical form
The same isotope is supplied in different forms: metal, oxide, carbonate, chloride, sulfate and other compounds. The form depends on the element and on how the material will be processed: target manufacturing, dissolution, sputtering or synthesis. Available forms are listed on each element page. If you need another form, mention it in your request and we will check.
What the lot passport contains
- isotopic composition — the shares of all isotopes of the element, not only the target one;
- chemical composition — impurity content;
- chemical form and mass;
- producer and lot information.
Before ordering, compare not only the enrichment of the target isotope but also the content of neighbouring isotopes: for some tasks they are critical. A sample and analysis in an independent laboratory are available on request.
What to include in a request
The isotope, the minimum acceptable enrichment, chemical form, quantity and field of application. This helps us find a suitable lot faster. See also “How to order a stable isotope” and isotope selections by task in Applications.
We send a quotation with price, lead time and specification within 1–2 business days. The price depends on the isotope, enrichment, form and quantity.