Performing An Isotope Dilution Analysis - Agilent Technologies 7500 ICP-MS Operator's Manual

Agilent 7500 ICP-MS ChemStation Operator's Manual

Performing an Isotope Dilution Analysis

Performing an Isotope
Dilution Analysis
Isotope dilution (ID) is an analytical technique used when the highest accuracy is
demanded. Typical applications include the certification of standards and reference
materials. ID is highly accurate since it uses known isotopic ratios to quantify
analyte concentration. Since isotope ratios can be measured with much greater
precision than elemental concentrations (~0.2% vs. 5%), this translates to greater
accuracy in ID determinations.
To be able to use ID to measure a given element, the element must possess 2 inter-
ference free isotopes, and a non-natural elemental spike must be readily available. A
known amount of an elemental spike is added to a known amount of the sample. The
chosen isotope ratio is measured. Since the spike isotope ratio, spike amount, and
sample amount are known, the original analyte concentration can be calculated. The
ChemStation ID software automatically calculates the analyte concentration after
the required data is entered.
Data files to be used for isotope dilution analysis should be acquired in the isotope
ratio acquisition mode.
This chapter explains how to set isotope dilution analysis parameters and generate
the isotope dilution analysis report.
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