Page 15 - Analityka 1/2015

Isotope dilution mass NAUKA
spectrometry: partly lightly
and partly seriously

PART I
In the first part the light introduction from the point of view of ecology through the prin-
ciple of the determination of the population of individuals by ornithologists in a closed
ecosystem, the chemical model of isotopic dilution is given. Then, more seriously, the
issues related to the isotope dilution mass spectrometry (IDMS) in elemental analysis
were presented. The introduction of the isotope dilution was associated with the devel-
opment of mass spectrometry, especially with the ability to perform measurements with
sufficient resolution and results with expected precision and accuracy. The basic equation
of IDMS includes the principles input quantities and allows to calculate the total content
of a given element in a sample. It should be emphasized that the isotope dilution mass
spectrometry fulfill the criteria set for a primary method, and is considered as such. In this
article, the sample preparation procedure before measurements of the altered isotope
ratios with metrological weighting step, as well as the time necessary to achieve isotopic
equilibrium in the mixture of sample and isotopically enriched standard after the metro-
logical weighing were highlighted. Both these factors have the critical influence on the
accuracy of results. Laboratory efforts during the sample preparation procedure are fully
compensated by the benefits of IDMS technique, which will be discussed in the next issue
of „Analityka”.

ANALITYKA – NUMER 1, ROK (XVI) 2015 29