Basic Training 4th Annual ICP Conference

16.22 ICP-MS Measurement

Quantitative Analysis Measurement Techniques - Isotope Dilution

• The technique of isotope dilu3on ICP mass spectrometry (ID-ICP-MS) provides the analyst with the possibility of using a primary (defini3ve) analy3cal method for the determina3on of trace metals in a variety of sample types. • Examples of primary analy3cal methods are isotope dilu3on mass spectrometry (IDMS), ID- ICP-MS, gravimetry, 3trimetry, coulometry, differen3al scanning calorimetry and nuclear magne3c resonance spectroscopy. • ID-ICP-MS should be of par3cular interest to the Reference Material producer of materials for trace metals content. Unfortunately, there are several of the elements that are monoisotopic (9Be, 23Na, 27Al, 45Sc, 55Mn, 75As, 89Y, 103Rh, 127I, 133Cs, 141Pr, 159Tb, 165Ho, 169Tm, 197Au, and 232Th), making ID-ICP-MS useless for these elements. • Our laboratory has been studying ID-ICP-MS along with the execu3on of accurate isotopic abundance ra3o measurements (another possible primary method) and will publish these studies in the months to come

17.1 Method Validation

The process of solving a problem, whether involved or rela7vely straigh9orward, involves a logical process. The phases of this process are as follows :

• Phase 1: Problem Defini2on and Planning • Phase 2: Method Selec2on • Phase 3: Method Development • Phase 4: Method Valida2on • Method Established • Phase 5: Method Applica2on

• Phase 6: Data Evalua2on • Phase 7: Data Published • Problem Solved