Quantitative analyses of trace and ultra-trace elements are performed by using a mass spectrometer with inductively coupled plasma source (ICP-MS) and quadrupole analyzer. Typically the samples analyzed are liquid solutions injected into the system and then ionized by the plasma. However, the concentrations of elements can be analyzed directly from solid matrix by laser ablation.

The Secondary Ion Mass Spectrometry (SIMS) allow the surface analysis of conductive and insulating materials, with the possibility of having the qualitative determination of almost all elements up to concentrations of ppm or, for some elements , ppb. The principle of operation is as follows: the sample to be analyzed is placed in a chamber at 10^-9 mbar and is sputtered by a collimated beam of O²⁺ ions bombarding the surface and causing the emission of particles and their ionization. These particles are focused into the analyzer quadrupole and identified as mass/charge ratio. The potential of the sample surface (if insulator) is compensated with a low energy electrons beam. With this technique the elemental in-depth distribution up to few µm depth can also be analyzed.