Adsorption in gas mass spectrometry - I. Effects on the measurement of individual isotopic species
Adsorption-desorption of gas molecules on the walls of the mass spectrometer inlet system have been studied in order to assess quantitatively their effects on isotope amount ratio measurements. The effects of adsorption in individual isotopic species are discussed, with emphasis on SiF(4) measurements which are required for the re-determination of the Avogadro constant. A model based on the Langmuir adsorption isotherm is developed; A parameter called 'apparent leak rate coefficient' is introduced, which represents the relative variation with time of any isotopic species in the inlet system. All the adsorption parameters appearing in the balance equations can be derived from the apparent leak rate coefficient.
Bibliographic Reference: Article: International Journal of Mass Spectrometry and Ion Processes (1996)
Record Number: 199611389 / Last updated on: 1996-12-18
Original language: en
Available languages: en