Search results for " MC-ICP-MS"
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Triple Isotope Fractionation Exponents of Elements Measured by MC-ICP-MS—An Example of Mg
2019
In most chemical reactions, stable isotopes are fractionated in a mass-dependent manner, yielding correlated isotope ratios in elements with three or more stable isotopes. The proportionality between isotope ratios is set by the triple isotope fractionation exponent θ that can be determined precisely for, e.g., sulfur and oxygen by IRMS, but not for metal(loid) elements due to the lower precision of MC-ICP-MS analysis and smaller isotopic variations. Here, using Mg as a test case, we compute a complete metrologically robust uncertainty budget for apparent θ values and, with reference to this, present a new measurement approach that reduces uncertainty on θ values by 30%. T…
Calcium Carbonate and Phosphate Reference Materials for Monitoring Bulk and Microanalytical Determination of Sr Isotopes
2017
In situ laser ablation analyses rely on the microanalytical homogeneity of reference materials (RMs) and a similar matrix and mass fraction between unknown samples and RMs to obtain reliable results. Suitable carbonate and phosphate RMs for determination of Sr isotope ratios in such materials are limited. Thus, we determined Sr-87/Sr-86 ratios of several carbonate (JCt-1, JCp-1, MACS-1, MACS-3) and phosphate (MAPS-4, MAPS-5, NIST SRM 1400, NIST SRM 1486) international RMs using dissolved samples and two different multi-collector inductively coupled plasma-mass spectrometers (MC-ICP-MS). Our Sr isotope data are in agreement with published data and have an improved measurement precision for s…