The calibration of Si isotope ratio measurements

Novel concept for the mass spectrometric determination of absolute isotopic abundances with improved measurement uncertainty: Part 2 – Development of an experimental procedure for the determination of the molar mass of silicon using MC-ICP-MS

“…A new mathematical closed-form method has recently been developed for the experimental determination of these K factors during the ICP-MS experiment [7]. For this purpose two blends b1 and b2 prepared from three independent isotopically different parent materials x, y and z were mixed gravimetrically.…”

“…The one step preparation ensures a chemical transfer being quantitative, corresponding to a 100% recovery -extremely difficult to realize in the case of the SiF 4 -route. Finally, a modified IDMS technique -described in detail in part 1 [6] -using a so-called virtual element (VE) -consisting of the minor abundant silicon isotopes 29 Si and 30 Si in their matrix namely the sum of all three Si isotopes ( 28 Si, 29 Si, 30 Si) in combination with a new analytical and non-iterative determination of calibration factors K [7] is applied. The combination of these innovations has been successfully performed at PTB for the first time using a silicon crystal material of natural isotopic abundance in order to give experimental proof of its applicability, prior to applying the new method to the extremely limited and thus expensive "Si28" Avogadro-crystal material [3].…”

Reducing the matrix effects in chemical analysis: fusion of isotope dilution and standard addition methods

“…Consequently, ID 3 MS was developed because it eliminates the need to know or measure this variable [7]. Building from this tradition, as exemplified in the recent works of Vogl [7], Mana and Rienitz [10], we also consider the question of how we can better measure the isotope ratios by enabling the possibility to perform matrix matching. In a way, matrix-matching isotope dilution is an extension of matching the measured isotope ratios [11] which is known to improve the quality of IDMS results.…”

Isotope amount ratio measurement challenge

“…Depending on the number of isotopes involved, the mathematical solutions become rather complex, and for several decades iterative calculations were thought to be unavoidable in this context. In the meantime, analytical solutions have been derived [8].…”