**4.4 Mass spectrometry with inductively coupled plasma (ICP-MS)**

ICP-MS (inductively coupled plasma-mass spectrometry) is a method for analyzing multi elements at trace levels in a range of liquid samples. It has a high level of precision and accuracy. As a result, solid materials must be digested before the examination, and digestion methods require the use of HNO3 or HNO3 and H2O2. In argon plasma, the material is atomized and ionized, and the resulting ions are sorted by a mass analyzer according to their mass-charge ratio (m/z) before being detected at the detector. The detection limits of this method are 0.2 ppt in solution and 0.1 ppb in tissues.
