In:
Journal of Analytical Atomic Spectrometry, Royal Society of Chemistry (RSC), Vol. 37, No. 9 ( 2022), p. 1869-1875
Abstract:
Here we present an analytical method for Fe isotopic measurements in low resolution mode, using a Nu Sapphire collision cell-equipped multi-collector inductively coupled plasma mass spectrometer by standard-sample bracketing. High Fe sensitivity was obtained through reducing Ar based interference by over 9 orders of magnitude whilst other analytes remained unaffected. The effects of Fe concentration, Fe beam intensity and HNO 3 molarity mismatch between the standard and sample and the presence of matrix elements have been evaluated. The long-term analyses of JMC Fe and BCR-2 indicate that the obtained isotopic ratios are highly reproducible, with precisions of better than ±0.03‰ for δ 56 Fe (2SD). Such accurate and precise data could be acquired via 3 to 6 repeat measurements consuming 50–100 ng Fe, which has improved by a factor 40 compared to those previously reported on other instruments. Accurate measurements were achieved by closely matching Fe intensities between the sample and standard (a 5% mismatch would create a 0.02‰ offset in the 56 Fe/ 54 Fe ratio). On the other hand, the ratio of the concentration between the matrix elements and Fe, such as C Na / C Fe , C Mg / C Fe , C Ca / C Fe , C Ti / C Fe and C Ni / C Fe , should be kept under 0.1, C K / C Fe under 0.3, C Al / C Fe and C Cu / C Fe under 1, and C Co / C Fe and C Zn / C Fe under 2 to avoid any matrix effect. In addition, high precision Fe isotopic data were obtained on twenty-one geological reference materials and were highly consistent with the literature values. Furthermore, we obtained δ 56 Fe of standard chalcopyrite (XTC) for the first time: 0.127 ± 0.027‰ (2SD, n = 3).
Type of Medium:
Online Resource
ISSN:
0267-9477
,
1364-5544
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
1484654-8
detail.hit.zdb_id:
54176-X
SSG:
11
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