"Mass spectrometry is a destructive method used to determine molecular weight and provide information on molecular structure; it is different from the other methods in that the sample is ionized and not subject to electromagnetic radiation. Thermal ionization mass spectrometry (TIMS) is a highly sensitive isotope mass spectrometry characterization technique that exploits the thermal ionization effect, in which a chemically purified sample is heated to cause ionization of the atoms of the sample. Thermal ionization mass spectrometry, or TIMS, has long been used as a standard method for very precise determination of isotope ratios in fields such as isotope geology. TIMS is used for isotope systems that in the natural environment can be found in the solid phase (U, Pb, Sr, Os, B, and Li). TIMS requires time-consuming sample preparation to ensure high quality chemical separation of the analyte. It is also important to correct for isotopic fractionation, particularly in the ion source. This volume Thermal Ionization Mass Spectrometry presents a comprehensive and systematic approach, reviewing all the steps involved in an analytical workflow. The text covers an introduction to the main ionization techniques in mass spectrometry and the way the resulting fragments can be analyzed. The fundamental concepts of mass spectrometry are explained, so that the reader can easily cover this topic (graphs, main pick, molecular ion, illogical pick, nitrogen rule, etc.). Isotopic percentage and nominal mass calculation are also explained along with fragmentation mechanism. An emphasis on the ionization energy issues, the basics of ionization voltage, the developing potential and the energy balance is also given. A frame time of the main theoretical milestones in both theory and experimental mass spectrometry is highlighted. Furthermore, it discusses applications of ICP-MS and comprehensive procedures on sample preparation and mass spectrometric measurements, plentiful practical intimation are given. This comprehensive guide will be of invaluable for all engineering students and anyone involved in isotope analysis."