Inductively coupled plasma mass spectrometry
Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry that is highly sensitive. It can see  a range of metals and several non-metals at concentrations below one part in 1012 (part per trillion). It is based on hooking together an inductively coupled plasma as a method of producing ions (ionization) with a mass spectrometer as a method of separating and detecting the ions. Many chemists use Argon as a carrier gas to make the plasma. The machine sends the sample ions through a series of small cones.  The cones let the plasma ions slowly enter the vacuum chamber of the mass spectrometer.