e-mail: dweis@eos.ubc.ca
phone / tél.: 1-604-822.1697
mobile: 778-386.4466
instrument

Analytical Developments and High-Precision Characterization of Reference Materials

The instruments housed at the Pacific Centre for Isotopic and Geochemical Research (PCIGR; pcigr.eos.ubc.ca) have become critical to the advancement of research in geochemical, environmental and medical fields. The nature of these analytical instruments requires very careful assessment of the accuracy and significance that can be attached to the results. How well do we know the absolute values of reference materials? What are the matrix effects? Such questions and more must be asked when developing new analytical schemes.

nu tims
Nu TIMS

 

Under Dominique’s guidance, the precision on Nd, Hf and Pb isotopic analyses is significantly better than 100 ppm (0.01%). PCIGR has established a high-precision database of reference materials, from felsic to ultramafic compositions to synthetic solutions, together with quality control protocols to monitor accuracy and precision (Weis et al., 2005, 2006 and 2007). The role of leaching (Nobre-Silva et al., 2009, 2010), mineralogy (Hanano et al., 2009) and matrix effects (Barling and Weis, 2008, 2012) on the precision and accuracy of MC-ICP-MS analyses for both radiogenic and heavy stable isotopes have been thoroughly investigated.

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143Nd/144Nd variations throughout the acid leaching procedure for basalts from (a) Mauna Loa, (b) Mauna Kea, (c) Mont Crozier, and (d) Northern Kerguelen Plateau (Nobre Silva et al., 2010).

 

BSE images and qualitative energy-dispersive spectra from regions of basalt sample J2-019-04 (Mauna Loa, Hawaii). (Hanano et al., 2009).

 

The results provide a solid reference basis for the scientific community and influence how researchers conduct their sample preparation and instrumental analyses. Our work on matrix effects (Barling and Weis, 2008, 2012), one of the first of its kind for isotopic ratios, has had a significant impact in particular.

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With the introduction of the new instruments in nUBC, and an extension of the PCIGR’s analytical pool, we have designed new experiments, for example to understand the effect of oxide formation on instrumental mass bias. Also, in collaboration with Nu Instruments engineers through a research and development partnership, we are looking to improve the limits of sensitivity of the instruments.

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