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Precise δ88/86Sr Determination on MC-ICP-MS
Natural fractionation of stable Sr isotopes (δ88/86Sr) has attracted increasing attention as it serves as a new tracer to explore the biogeochemical process or source identification of Sr. As its applications have been expanded in various research fields, a highly efficient, accurate, and precise analytical method for δ88/86Sr determination is bound to be needed. NSI has a variety of techniques for accurately determining stable strontium isotopes on MC-ICP-MS.

Precise δ88/86Sr determination on MC-ICP-MS by an improved method combined Zr-empirical external normalization isobaric interference correction and 84Sr-87Sr double spike

Journal of Analytical Atomic Spectrometry, doi:10.1039/D1JA00224D

The most accurate and precise δ88/86Sr determination is performed by using the double spikes (DS) technique on TIMS. However, TIMS is always subjected to its long data acquisition time over MC-ICP-MS. We present a novel approach, combing the use of Zr-EEN for Kr and Rb isobaric interference correction and 84Sr-87Sr DS to overcome the severe mass bias effects on the measured 88Sr/86Sr ratios, to improve the analytical accuracy of MC-ICP-MS δ88/86Sr determination.
The δ88/86Sr of the IAPSO seawater standard was determined to be 0.37‰±0.03 (2SD, n=16) with an internal precision of better than ±0.01‰ (2SE). By applying this new EEN-DS MC-ICP-MS method, the accuracy is significantly improved, which is comparable to DS TIMS.
Precise determination of triple Sr isotopes (δ87Sr and δ88Sr) using MC-ICP-MS

Talanta, 2012, 338-344, doi:10.1016/j.talanta.2011.10.050

We established a modified empirical external normalization (EEN) MC-ICP-MS procedure for mass bias correction in Sr isotopic measurement using 92Zr/90Zr. High-purity Zr Standard was spiked into sample solutions and the degree of fractionation was calculated offline using an exponential law. Compared with the 91Zr/90Zr-EEN method, our new method has significantly improved analytical accuracy and external precision.

Determination of 87Sr/86Sr and δ88/86Sr ratios in plant materials using MC-ICP-MS

Analytical and Bioanalytical Chemistry, 2016, 387-397, doi:10.1007/s00216-015-9070-y

We present a protocol for highly accurate and precise determination of Sr isotope ratios in plant materials, 87Sr/86Sr and δ88/86Sr, by MC-ICP-MS. An improved Zr empirical external normalization coupled with the standard-sample bracketing method (Zr EEN-SSB) was applied to mass bias correction during Sr isotope measurements. We argue that the partially remaining organic compounds in the incomplete digestion would significantly bias the extraction chromatography procedure, resulting in sizable uncertainty in δ88/86Sr ratios. Thus, complete digestion of the organic-enriched materials is of great importance for efficiency assurance in matrix separation.

🕑 Update:  February 7, 2022