3. Observed spectra

In the case of elemental analyses such as those carried out by ICP-MS, the spectra obtained are, in theory, relatively simple, since they only reflect the isotopic distributions of the elements present, i.e. approximately 210 different unit masses. This is because, in most cases, the isotopes are mono-ionized in the plasma; the mass-to-charge ratio analyzed is then comparable to the mass of the isotope. On the other hand, to a first approximation, the sensitivity of different isotopes of the same element is only proportional to isotopic abundance.