What are the limitations to correcting isotopic ratios?
My research at UBC, as a Ph.D. student and a MAGNET Trainee is focused on improving precision and accuracy in Multi Collector-Inductively Coupled Plasma-Mass Spectrometry.
MC-ICP-MS instruments are able to produce high-precision, high-accuracy ratio measurements for several of isotopic systems. Scientists from different areas use these measurements for a wide range of applications, such as fingerprints of the source of geologic samples, tracers for natural/anthropogenic processes that cause mass fractionation, and cosmo- and geochronology. Each of these applications requires various degrees of precision, making the constant and dynamic improvement of isotopic measurements paramount to several fields of science.
The isotopic ratios measured using MC-ICP-MS, however, are always biased from their “true” value due to mass fractionation caused by processes inherent to this technique. Generally, fractionation laws, double spiking or/and standard-sample bracketing (SSB) can correct for these discrepancies. However, some other minor sources of mass bias cannot be resolved in the same way.
My interest is in constraining and characterising different sources of mass fractionation that are introduced by this instrument, and that cannot be corrected for using traditional methods. As the outcome of this research, I intend on developing a set of analytical methods to correct, minimise, or overcome the impact of these phenomena on MC-ICP-MS measurements.
